Rules Index | GM Screen | Player's Guide


Chapter 9: Playing the Game

General Rules

Source Core Rulebook pg. 443 4.0
Before exploring the specific rules of each mode of play, you’ll want to understand a number of general rules of the game. To one degree or another, these rules are used in every mode of play.

Making Choices

Source Core Rulebook pg. 443 4.0
Pathfinder is a game where your choices determine the story’s direction. Throughout the game, the GM describes what’s happening in the world and then asks the players, “So what do you do?” Exactly what you choose to do, and how the GM responds to those choices, builds a unique story experience. Every game is different, because you’ll rarely, if ever, make the same decisions as another group of players. This is true for the GM as well—two GMs running the exact same adventure will put different emphasis and flourishes on the way they present each scenario and encounter.

Often, your choices have no immediate risk or consequences. If you’re traveling along a forest path and come across a fork in the trail, the GM will ask, “Which way do you go?” You might choose to take the right fork or the left. You could also choose to leave the trail, or just go back to town. Once your choice is made, the GM tells you what happens next. Down the line, that choice may impact what you encounter later in the game, but in many cases nothing dangerous happens immediately.

But sometimes what happens as a result of your choices is less than certain. In those cases, you’ll attempt a check.

Checks

Source Core Rulebook pg. 443 4.0
When success isn’t certain—whether you’re swinging a sword at a foul beast, attempting to leap across a chasm, or straining to remember the name of the earl’s second cousin at a soiree—you’ll attempt a check. Pathfinder has many types of checks, from skill checks to attack rolls to saving throws, but they all follow these basic steps.
  1. Roll a d20 and identify the modifiers, bonuses, and penalties that apply.
  2. Calculate the result.
  3. Compare the result to the difficulty class (DC).
  4. Determine the degree of success and the effect.
Checks and difficulty classes (DC) both come in many forms. When you swing your sword at that foul beast, you’ll make an attack roll against its Armor Class, which is the DC to hit another creature. If you are leaping across that chasm, you’ll attempt an Athletics skill check with a DC based on the distance you are trying to jump. When calling to mind the name of the earl’s second cousin, you attempt a check to Recall Knowledge. You might use either the Society skill or a Lore skill you have that’s relevant to the task, and the DC depends on how common the knowledge of the cousin’s name might be, or how many drinks your character had when they were introduced to the cousin the night before.

No matter the details, for any check you must roll the d20 and achieve a result equal to or greater than the DC to succeed. Each of these steps is explained below.

Step 1: Roll d20 and Identify the Modifiers, Bonuses, and Penalties that Apply

Source Core Rulebook pg. 444 4.0
Start by rolling your d20. You’ll then identify all the relevant modifiers, bonuses, and penalties that apply to the roll. A modifier can be either positive or negative, but a bonus is always positive, and a penalty is always negative. The sum of all the modifiers, bonuses, and penalties you apply to the d20 roll is called your total modifier for that statistic.

Nearly all checks allow you to add an ability modifier to the roll. An ability modifier represents your raw capabilities and is derived from an ability score, as described on page 20. Exactly which ability modifier you use is determined by what you’re trying to accomplish. Usually a sword swing applies your Strength modifier, whereas remembering the name of the earl’s cousin uses your Intelligence modifier.

When attempting a check that involves something you have some training in, you will also add your proficiency bonus. This bonus depends on your proficiency rank: untrained, trained, expert, master, or legendary. If you’re untrained, your bonus is +0—you must rely on raw talent and any bonuses from the situation. Otherwise, the bonus equals your character’s level plus a certain amount depending on your rank. If your proficiency rank is trained, this bonus is equal to your level + 2, and higher proficiency ranks further increase the amount you add to your level.

Proficiency Bonus

Proficiency RankProficiency Bonus
Untrained0
TrainedYour level + 2
ExpertYour level + 4
MasterYour level + 6
LegendaryYour level + 8


There are three other types of bonus that frequently appear: circumstance bonuses, item bonuses, and status bonuses. If you have different types of bonus that would apply to the same roll, you’ll add them all. But if you have multiple bonuses of the same type, you can use only the highest bonus on a given roll—in other words, they don’t “stack.” For instance, if you have both a proficiency bonus and an item bonus, you add both to your d20 result, but if you have two item bonuses that could apply to the same check, you add only the higher of the two.

Circumstance bonuses typically involve the situation you find yourself in when attempting a check. For instance, using Raise a Shield with a buckler grants you a +1 circumstance bonus to AC. Being behind cover grants you a +2 circumstance bonus to AC. If you are both behind cover and Raising a Shield, you gain only the +2 circumstance bonus for cover, since they’re the same type and the bonus from cover is higher.

Item bonuses are granted by some item that you are wearing or using, either mundane or magical. For example, armor gives you an item bonus to AC, while expanded alchemist’s tools grant you an item bonus to Crafting checks when making alchemical items.

Status bonuses typically come from spells, other magical effects, or something applying a helpful, often temporary, condition to you. For instance, the 3rd-level heroism spell grants a +1 status bonus to attack rolls, Perception checks, saving throws, and skill checks. If you were under the effect of heroism and someone cast the bless spell, which also grants a +1 status bonus on attacks, your attack rolls would gain only a +1 status bonus, since both spells grant a +1 status bonus to those rolls, and you only take the highest status bonus.

Penalties work very much like bonuses. You can have circumstance penalties, status penalties, and sometimes even item penalties. Like bonuses of the same type, you take only the worst all of various penalties of a given type. However, you can apply both a bonus and a penalty of the same type on a single roll. For example, if you had a +1 status bonus from a heroism spell but a –2 status penalty from the sickened condition, you’d apply them both to your roll—so heroism still helps even though you’re feeling unwell.

Unlike bonuses, penalties can also be untyped, in which case they won’t be classified as “circumstance,” “item,” or “status.” Unlike other penalties, you always add all your untyped penalties together rather than simply taking the worst one. For instance, when you use attack actions, you incur a multiple attack penalty on each attack you make on your turn after the first attack, and when you attack a target that’s beyond your weapon’s normal range increment, you incur a range penalty on the attack. Because these are both untyped penalties, if you make multiple attacks at a faraway target, you’d apply both the multiple attack penalty and the range penalty to your roll.

Once you’ve identified all your various modifiers, bonuses, and penalties, you move on to the next step.

Step 2: Calculate the Result

Source Core Rulebook pg. 445 4.0
This step is simple. Add up all the various modifiers, bonuses, and penalties you identified in Step 1—this is your total modifier. Next add that to the number that came up on your d20 roll. This total is your check result.

Step 3: Compare the Result to the DC

Source Core Rulebook pg. 445 4.0
This step can be simple, or it can create suspense. Sometimes you’ll know the Difficulty Class (DC) of your check. In these cases, if your result is equal to or greater than the DC, you succeed! If your roll anything less than the DC, you fail.

Other times, you might not know the DC right away. Swimming across a river would require an Athletics check, but it doesn’t have a specified DC—so how will you know if you succeed or fail? You call out your result to the GM and they will let you know if it is a success, failure, or otherwise. While you might learn the exact DC through trial and error, DCs sometimes change, so asking the GM whether a check is successful is the best way to determine whether or not you have met or exceeded the DC.

Calculating DCs

Source Core Rulebook pg. 445 4.0
Whenever you attempt a check, you compare your result against a DC. When someone or something else attempts a check against you, rather than both forces rolling against one another, the GM (or player, if the opponent is another PC) compares their result to a fixed DC based on your relevant statistic. Your DC for a given statistic is 10 + the total modifier for that statistic.

Step 4: Determine the Degree of Success

Source Core Rulebook pg. 445 4.0
Many times, it's important to determine not only if you succeed or fail, but also how spectacularly you succeed or fail. Exceptional results—either good or bad—can cause you to critically succeed at or critically fail a check.

You critically succeed at a check when the check's result meets or exceeds the DC by 10 or more. If the check is an attack roll, this is sometimes called a critical hit. You can also critically fail a check. The rules for critical failure—sometimes called a fumble—are the same as those for a critical success, but in the other direction: if you fail a check by 10 or more, that's a critical failure.

If you rolled a 20 on the die (a “natural 20”), your result is one degree of success better than it would be by numbers alone. If you roll a 1 on the d20 (a “natural 1”), your result is one degree worse. This means that a natural 20 usually results in a critical success and natural 1 usually results in a critical failure. However, if you were going up against a very high DC, you might get only a success with a natural 20, or even a failure if 20 plus your total modifier is 10 or more below the DC. Likewise, if your modifier for a statistic is so high that adding it to a 1 from your d20 roll exceeds the DC by 10 or more, you can succeed even if you roll a natural 1! If a feat, magic item, spell, or other effect does not list a critical success or critical failure, treat is as an ordinary success or failure instead.

Some other abilities can change the degree of success for rolls you get. When resolving the effect of an ability that changes your degree of success, always apply the adjustment from a natural 20 or natural 1 before anything else.

Specific Checks

Source Core Rulebook pg. 446 4.0
While most checks follow these basic rules, it’s useful to know about a few specific types of checks, how they’re used, and how they differ from one another.

Attack Rolls

Source Core Rulebook pg. 446 4.0
When you use a Strike action or make a spell attack, you attempt a check called an attack roll. Attack rolls take a variety of forms and are often highly variable based on the weapon you are using for the attack, but there are three main types: melee attack rolls, ranged attack rolls, and spell attack rolls. Spell attack rolls work a little bit differently, so they are explained separately on the next page.

Melee attack rolls use Strength as their ability modifier by default. If you're using a weapon or attack with the finesse trait, then you can use your Dexterity modifier instead.

Melee attack roll result = d20 roll + Strength modifier (or optionally Dexterity modifier for a finesse weapon) + proficiency bonus + other bonuses + penalties

Ranged attack rolls use Dexterity as their ability modifier.

Ranged attack roll result = d20 roll + Dexterity modifier + proficiency bonus + other bonuses + penalties

When attacking with a weapon, whether melee or ranged, you add your proficiency bonus for the weapon you're using. Your class determines your proficiency rank for various weapons. Sometimes, you'll have different proficiency ranks for different weapons. For instance, at 5th level, a fighter gains the weapon mastery class feature, which grants master proficiency with the simple and martial weapons of one weapon group, expert proficiency with advanced weapons of that group and other simple and martial weapons, and trained proficiency in all other advanced weapons.

The bonuses you might apply to attack rolls can come from a variety of sources. Circumstance bonuses can come from the aid of an ally or a beneficial situation. Status bonuses are typically granted by spells and other magical aids. The item bonus to attack rolls comes from magic weapons—notably, a weapon's potency rune.

Penalties to attack rolls come from situations and effects as well. Circumstance penalties come from risky tactics or detrimental circumstances, status penalties come from spells and magic working against you, and item penalties occur when you use a shoddy item (page 273). When making attack rolls, two main types of untyped penalties are likely to apply. The first is the multiple attack penalty, and the second is the range penalty. The first applies anytime you make more than one attack action during the course of your turn, and the other applies only with ranged or thrown weapons. Both are described below.

Multiple Attack Penalty

Source Core Rulebook pg. 446 4.0
The more attacks you make beyond your first in a single turn, the less accurate you become, represented by the multiple attack penalty. The second time you use an attack action during your turn, you take a –5 penalty to your check. The third time you attack, and on any subsequent attacks, you take a –10 penalty to your check. Every check that has the attack trait counts toward your multiple attack penalty, including Strikes, spell attack rolls, certain skill actions like Shove, and many others.

Some weapons and abilities reduce multiple attack penalties, such as agile weapons, which reduce these penalties to –4 on the second attack or –8 on further attacks.

Multiple Attack Penalty

AttackMultiple Attack PenaltyAgile
FirstNoneNone
Second-5-4
Third and subsequent-10-8


Always calculate your multiple attack penalty for the weapon you're using on that attack. For example, let's say you're wielding a longsword in one hand and a shortsword (which has the agile trait) in your other hand, and you are going to make three Strikes with these weapons during the course of your turn. The first Strike you make during your turn has no penalty, no matter what weapon you are using. The second Strike will take either a –5 penalty if you use the longsword or a –4 penalty if you use the shortsword. Just like the second attack, the penalty for your third attack is based on which weapon you're using for that particular Strike. It would be a –10 penalty with the longsword and a –8 penalty with the shortsword, no matter what weapon you used for your previous Strikes.

The multiple attack penalty applies only during your turn, so you don't have to keep track of it if you can perform an Attack of Opportunity or a similar reaction that lets you make a Strike on someone else's turn.

Range Penalty

Source Core Rulebook pg. 446 4.0
Ranged and thrown weapons each have a listed range increment, and attacks with them grow less accurate against targets farther away (range and range increments are covered in depth on page 279). As long as your target is at or within the listed range increment, also called the first range increment, you take no penalty to the attack roll. If you’re attacking beyond that range increment, you take a –2 penalty for each additional increment beyond the first. You can attempt to attack with a ranged weapon or thrown weapon up to six range increments away, but the farther away you are, the harder it is to hit your target.

For example, the range increment of a crossbow is 120 feet. If you are shooting at a target no farther away than that distance, you take no penalty due to range. If they’re beyond 120 feet but no more than 240 feet away, you take a –2 penalty due to range. If they’re beyond 240 feet but no more than 360 feet away, you take a –4 penalty due to range, and so on, until you reach the last range increment: beyond 600 feet but no more than 720 feet away, where you take a –10 penalty due to range.

Armor Class

Source Core Rulebook pg. 447 4.0
Attack rolls are compared to a special difficulty class called an Armor Class (AC), which measures how hard it is for your foes to hit you with Strikes and other attack actions. Just like for any other check and DC, the result of an attack roll must meet or exceed your AC to be successful, which allows your foe to deal damage to you.

Armor Class is calculated using the following formula.

Armor Class = 10 + Dexterity modifier (up to your armor’s Dex Cap) + proficiency bonus + armor’s item bonus to AC + other bonuses + penalties

Use the proficiency bonus for the category (light, medium, or heavy) or the specific type of armor you’re wearing. If you’re not wearing armor, use your proficiency in unarmored defense.

Armor Class can benefit from bonuses with a variety of sources, much like attack rolls. Armor itself grants an item bonus, so other item bonuses usually won’t apply to your AC, but magic armor can increase the item bonus granted by your armor.

Penalties to AC come from situations and effects in much the same way bonuses do. Circumstance penalties come from unfavorable situations, and status penalties come from effects that impede your abilities or from broken armor. You take an item penalty when you wear shoddy armor.

Spell Attack Rolls

Source Core Rulebook pg. 447 4.0
If you cast spells, you might be able to make a spell attack roll. These rolls are usually made when a spell makes an attack against a creature’s AC.

The ability modifier for a spell attack roll depends on how you gained access to your spells. If your class grants you spellcasting, use your key ability modifier. Innate spells use your Charisma modifier unless the ability that granted them states otherwise. Focus spells and other sources of spells specify which ability modifier you use for spell attack rolls in the ability that granted them. If you have spells from multiple sources or traditions, you might use different ability modifiers for spell attack rolls for these different sources of spells. For example, a dwarf cleric with the Stonewalker ancestry feat would use her Charisma modifier when casting meld into stone from that feat, since it’s a divine innate spell, but she would use her Wisdom modifier when casting heal and other spells using her cleric divine spellcasting.

Determine the spell attack roll with the following formula.

Spell attack roll result = d20 roll + ability modifier used for spellcasting + proficiency bonus + other bonuses + penalties

If you have the ability to cast spells, you’ll have a proficiency rank for your spell attack rolls, so you’ll always add a proficiency bonus. Like your ability modifier, this proficiency rank may vary from one spell to another if you have spells from multiple sources. Spell attack rolls can benefit from circumstance bonuses and status bonuses, though item bonuses to spell attack rolls are rare. Penalties affect spell attack rolls just like any other attack roll—including your multiple attack penalty.

Many times, instead of requiring you to make a spell attack roll, the spells you cast will require those within the area or targeted by the spell to attempt a saving throw against your Spell DC to determine how the spell affects them.

Your spell DC is calculated using the following formula.

Spell DC = 10 + ability modifier used for spellcasting + proficiency bonus + other bonuses + penalties


Perception

Source Core Rulebook pg. 448 4.0
Perception measures your ability to be aware of your environment. Every creature has Perception, which works with and is limited by a creature's senses (described on page 464). Whenever you need to attempt a check based on your awareness, you'll attempt a Perception check. Your Perception uses your Wisdom modifier, so you'll use the following formula when attempting a Perception check.

Perception check result = d20 roll + Wisdom modifier + proficiency bonus + other bonuses + penalties

Nearly all creatures are at least trained in Perception, so you will almost always add a proficiency bonus to your Perception modifier. You might add a circumstance bonus for advantageous situations or environments, and typically get status bonuses from spells or other magical effects. Items can also grant you a bonus to Perception, typically in a certain situation. For instance, a fine spyglass grants a +1 item bonus to Perception when attempting to see something a long distance away. Circumstance penalties to Perception occur when an environment or situation (such as fog) hampers your senses, while status penalties typically come from conditions, spells, and magic effects that foil the senses. You'll rarely encounter item penalties or untyped penalties for Perception.

Many abilities are compared to your Perception DC to determine whether they succeed. Your Perception DC is 10 + your total Perception modifier.
Item Bonsues for Common items
Ability/SkillItemBonusLevelCategoryConsumable?Note
PerceptionMagnifying Glass+13Adventuring GearNoPerception checks to notice minute details of documents, fabric, and the like
PerceptionMagnifying Scope+13ScopesNoVisual Perception checks to Seek creatures through the scope
PerceptionSpyglass (Fine)+14Adventuring GearNoPerception checks to notice details at a distance
PerceptionEye Slash (Greater)+14TattoosNoVisual Perception checks
PerceptionGoggles of Night+15Other Worn ItemsNoPerception checks involving sight
PerceptionDarkvision Scope+15ScopesNoPerception checks involving sight in areas of dim light visible through the scope (as well as in areas of darkness, if the scope has been activated).
PerceptionMirror Goggles (Lesser)+15Other Worn ItemsNoVisual Perception checks
PerceptionObsidian Goggles+15Other Worn ItemsNoPerception checks involving sight
PerceptionEye of the Unseen+18ProsthesesNoVisual Perception checks
PerceptionClarity Goggles (Lesser)+18Other Worn ItemsNoVisual Perception checks
PerceptionCodex of Unimpeded Sight (Greater)+112GrimoiresNoPerception checks to Seek
PerceptionEagle-Eye Elixir (Lesser)+11Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
PerceptionSerene Mutagen (Lesser)+11Alchemical ElixirsYes
PerceptionDrakeheart Mutagen (Lesser)+11Alchemical ElixirsYes
DiplomacyDiplomat's Charcuterie+13Alchemical FoodYesDiplomacy checks to Make an Impression
PerceptionEyes of the Eagle+29Other Worn ItemsNoPerception checks that involve sight
PerceptionMagnifying Scope (Greater)+29ScopesNoVisual Perception checks to Seek creatures through the scope
PerceptionEye Slash (Major)+29TattoosNoVisual Perception checks
PerceptionJann's Prism+29Held ItemsNovisual Perception checks
PerceptionSun Sight+210TattoosNoVisual Perception checks
PerceptionGoggles of Night (Greater)+211Other Worn ItemsNoPerception checks involving sight
PerceptionMirror Goggles (Moderate)+211Other Worn ItemsNoVisual Perception checks
PerceptionObsidian Goggles (Greater)+211Other Worn ItemsNoPerception checks involving sight
PerceptionSpectacles of Inquiry+212Other Worn ItemsNo
PerceptionScope of Truth+213ScopesNoPerception checks made to Seek in areas you can see through the scope
PerceptionClarity Goggles (Moderate)+213Other Worn ItemsNoVisual Perception checks
PerceptionEye of the Unseen (Greater)+214ProsthesesNoVisual Perception checks
PerceptionDarkvision Scope (Greater)+215ScopesNoPerception checks involving sight in areas of dim light visible through the scope (as well as in areas of darkness, if the scope has been activated).
PerceptionAmulet of the Third Eye+217Other Worn ItemsNo
PerceptionSerene Mutagen (Moderate)+23Alchemical ElixirsYes
PerceptionDrakeheart Mutagen (Moderate)+23Alchemical ElixirsYes
PerceptionZerk+24DrugsYesPerception rolls for initiative
PerceptionEagle-Eye Elixir (Moderate)+25Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
PerceptionMagnifying Scope (Major)+317ScopesNoVisual Perception checks to Seek creatures through the scope
PerceptionEye Slash (True)+317TattoosNoVisual Perception checks
PerceptionGoggles of Night (Major)+318Other Worn ItemsNoPerception checks involving sight
PerceptionMirror Goggles (Greater)+318Other Worn ItemsNoVisual Perception checks
PerceptionObsidian Goggles (Major)+318Other Worn ItemsNoPerception checks involving sight
PerceptionThird Eye+319Other Worn ItemsNo
PerceptionClarity Goggles (Greater)+319Other Worn ItemsNoVisual Perception checks
PerceptionEagle-Eye Elixir (Greater)+310Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
PerceptionSerene Mutagen (Greater)+311Alchemical ElixirsYes
PerceptionDrakeheart Mutagen (Greater)+311Alchemical ElixirsYes
PerceptionEagle-Eye Elixir (Major)+316Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
PerceptionSerene Mutagen (Major)+417Alchemical ElixirsYes
PerceptionDrakeheart Mutagen (Major)+417Alchemical ElixirsYes
Item Bonsues for Uncommon/Rare/Unique items
Ability/SkillItemBonusLevelCategoryConsumable?Note
PerceptionHigh-Contrast Goggles+10Adventuring GearNo
PerceptionVestige Lenses+13Alchemical OtherNoPerception checks to Seek any alchemical vapors
PerceptionSkinsaw Mask+13Other Worn ItemsNoPerception checks to Seek frightened creatures
PerceptionStalk Goggles (Greater)+13Other Worn ItemsNoPerception checks involving sight
PerceptionSkinsaw Mask+13Other Worn ItemsNoSeek frightened creatures
PerceptionSleuth's Pipe+13Relic SeedsNoPerception checks to Sense Motive
PerceptionCovenant Tea+13TeaNoTo Perception DC
PerceptionSeer's Flute+14CodaNowhile playing the flute
PerceptionRing of the Tiger +15Other Worn ItemsNoPerception checks made in outdoor wilderness areas
PerceptionStag's Helm+16Other Worn ItemsNo
PerceptionGhost Scarf+17Held ItemsNoAll Perception checks and Perception DCs to resolve discovering a haunt or rolling initiative when a haunt triggers.
PerceptionSpiritsight Tea+17TeaNoPerception checks to Seek incorporeal creatures.
PerceptionUmbral Wings+18Other Worn ItemsNoChecks to Seek
PerceptionSeer's Flute (Greater)+18CodaNowhile playing the flute
PerceptionDiviner's Nose Chain+19Other Worn ItemsNoSeek or Sense Motive
PerceptionDrazmorg's Staff of All-Sight+110StavesNoVisual Perception checks
PerceptionSkeptic's Elixir (Lesser)+11Alchemical ElixirsYesPerception checks and Perception DCs to notice falsehoods, whether they're spoken lies or written deceit
PerceptionGrim Ring+25Other Worn ItemsNoSecret Perception checks against undead in the area that are hiding or disguised
PerceptionSpiritsight Ring+26Other Worn ItemsNoSeek to find hidden or undetected incorporeal creatures within 30 feet of you
PerceptionStalk Goggles (Major)+28Other Worn ItemsNoPerception checks involving sight
PerceptionStarless Scope+29Held ItemsNoPerception checks made to observe the skies
PerceptionAeon Stone (Cymophane Cabochon)+29Other Worn ItemsNo
PerceptionRing of the Tiger (Greater)+210Other Worn ItemsNoPerception checks made in outdoor wilderness areas
PerceptionSpectral Opera Glasses+211Held ItemsNo
PerceptionBring Me Near+212Held ItemsNoVisual Perception checks
PerformanceSeer's Flute (Major)+212CodaNowhile playing the flute
PerceptionExploration Lens (Searching)+214Held ItemsNoPerception checks to spot hidden doors and concealed hazards while Searching
PerceptionThe Big Sky+220The Deck of DestinyNoPerception checks made while flying outside during the day (+3 at 17th level)
PerceptionThe Trumpet+220The Deck of DestinyNoinitiative checks made with hearing-based Perception checks
PerceptionThe Owl+220The Deck of DestinyNoPerception checks made to Sense Motive (+3 at 17th level).
PerceptionThe Inquisitor+220The Deck of DestinyNoPerception checks to Sense Motive against creatures higher level than you (+3 at 17th level).
PerceptionThe Unicorn+220The Deck of DestinyNoPerception checks to Seek (+3 at 17th level).
PerceptionThe Winged Serpent+220The Deck of DestinyNosight-based Perception checks for initiative (+3 at 17th level).
PerceptionSkeptic's Elixir (Moderate)+26Alchemical ElixirsYesPerception checks and Perception DCs to notice falsehoods, whether they're spoken lies or written deceit
PerceptionOmmatophoric Mutagen+27Alchemical ElixirsYesvisual Perception checks
PerceptionPallesthetic Mutagen+29Alchemical ElixirsYesPerception checks using the granted senses
PerceptionEnergizing Pill+210Alchemical FoodYesItem bonus to initiative rolls with Perception.
PerceptionDragonfly Potion+212PotionsYesVisual Perception checks
PerceptionRobe of Eyes+317Other Worn ItemsNo
PerceptionVoid Mirror+320ArtifactsNoPerception checks made while using the mirror
PerceptionSkeptic's Elixir (Greater)+311Alchemical ElixirsYesPerception checks and Perception DCs to notice falsehoods, whether they're spoken lies or written deceit

Perception for Initiative

Source Core Rulebook pg. 448 4.0
Often, you’ll roll a Perception check to determine your order in initiative. When you do this, instead of comparing the result against a DC, everyone in the encounter will compare their results. The creature with the highest result acts first, the creature with the second-highest result goes second, and so on. Sometimes you may be called on to roll a skill check for initiative instead, but you’ll compare results just as if you had rolled Perception. The full rules for initiative are found in the rules for encounter mode on page 468.

Saving Throws

Source Core Rulebook pg. 448 4.0
There are three types of saving throws: Fortitude saves, Reflex saves, and Will saves. In all cases, saving throws measure your ability to shrug off harmful effects in the form of afflictions, damage, or conditions. You'll always add a proficiency bonus to each save. Your class might give a different proficiency to each save, but you'll be trained at minimum. Some circumstances and spells might give you circumstance or status bonuses to saves, and you might find resilient armor or other magic items that give an item bonus.

Fortitude saving throws allow you to reduce the effects of abilities and afflictions that can debilitate the body. They use your Constitution modifier and are calculated as shown in the formula below.

Fortitude save result = d20 roll + Constitution modifier + proficiency bonus + other bonuses + penalties

Reflex saving throws measure how well you can respond quickly to a situation and how gracefully you can avoid effects that have been thrown at you. They use your Dexterity modifier and are calculated as shown in the formula below.

Reflex save result = d20 roll + Dexterity modifier + proficiency bonus + other bonuses + penalties

Will saving throws measure how well you can resist attacks to your mind and spirit. They use your Wisdom modifier and are calculated as shown in the formula below.

Will save result = d20 roll + Wisdom modifier + proficiency bonus + other bonuses + penalties

Sometimes you'll need to know your DC for a given saving throw. The DC for a saving throw is 10 + the total modifier for that saving throw.

Most of the time, when you attempt a saving throw, you don't have to use your actions or your reaction. You don't even need to be able to act to attempt saving throws. However, in some special cases you might have to take an action to attempt a save. For instance, you can try to recover from the sickened condition by spending an action to attempt a Fortitude save.

Basic Saving Throws

Source Core Rulebook pg. 449 4.0
Sometimes you will be called on to attempt a basic saving throw. This type of saving throw works just like any other saving throw—the “basic” part refers to the effects. For a basic save, you’ll attempt the check and determine whether you critically succeed, succeed, fail, or critically fail like you would any other saving throw. Then one of the following outcomes applies based on your degree of success—no matter what caused the saving throw.

Critical Success You take no damage from the spell, hazard, or effect that caused you to attempt the save.
Success You take half the listed damage from the effect.
Failure You take the full damage listed from the effect.
Critical Failure You take double the listed damage from the effect.

Skill Checks and Skill DCs

Source Core Rulebook pg. 449 4.0
Pathfinder has a variety of skills, from Athletics to Medicine to Occultism. Each grants you a set of related actions that rely on you rolling a skill check. Each skill has a key ability score, based on the scope of the skill in question. For instance, Athletics deals with feats of physical prowess, like swimming and jumping, so its key ability score is Strength. Medicine deals with the ability to diagnose and treat wounds and ailments, so its key ability score is Wisdom. The key ability score for each skill is listed in Chapter 4: Skills. No matter which skill you’re using, you calculate a check for it using the following formula.

Skill check result = d20 roll + modifier of the skill’s key ability score + proficiency bonus + other bonuses + penalties

You’re unlikely to be trained in every skill. When using a skill in which you’re untrained, your proficiency bonus is +0; otherwise, it equals your level plus 2 for trained, or higher once you become expert or better. The proficiency rank is specific to the skill you’re using. Aid from another character or some other beneficial situation may grant you a circumstance bonus. A status bonus might come from a helpful spell or magical effect. Sometimes tools related to the skill grant you an item bonus to your skill checks. Conversely, unfavorable situations might give you a circumstance penalty to your skill check, while harmful spells, magic, or conditions might also impose a status penalty. Using shoddy or makeshift tools might cause you to take an item penalty. Sometimes a skill action can be an attack, and in these cases, the skill check might take a multiple attack penalty, as described on page 446.

When an ability calls for you to use the DC for a specific skill, you can calculate it by adding 10 + your total modifier for that skill.

Notating Total Modifiers

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When creating your character and adventuring you’ll record the total modifier for various important checks on your character sheet. Since many bonuses and penalties are due to the immediate circumstances, spells, and other temporary magical effects, you typically won’t apply them to your notations.

Item bonuses and penalties are often more persistent, so you will often want to record them ahead of time. For instance, if you are using a weapon with a +1 weapon potency rune, you’ll want to add the +1 item bonus to your notation for your attack rolls with that weapon, since you will include that bonus every time you attack with that weapon. But if you have a fine spyglass, you wouldn’t add its item bonus to your Perception check notation, since you gain that bonus only if you are using sight—and the spyglass!—to see long distances.

Special Checks

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Some categories of checks follow special rules. The most notable are flat checks and secret checks.

Flat Checks

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When the chance something will happen or fail to happen is based purely on chance, you’ll attempt a flat check. A flat check never includes any modifiers, bonuses, or penalties—you just roll a d20 and compare the result on the die to the DC. Only abilities that specifically apply to flat checks can change the checks’ DCs; most such effects affect only certain types of flat checks.

If more than one flat check would ever cause or prevent the same thing, just roll once and use the highest DC. In the rare circumstance that a flat check has a DC of 1 or lower, skip rolling; you automatically succeed. Conversely, if one ever has a DC of 21 or higher, you automatically fail.

Secret Checks

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Sometimes you as the player shouldn’t know the exact result and effect of a check. In these situations, the rules (or the GM) will call for a secret check. The secret trait appears on anything that uses secret checks. This type of check uses the same formulas you normally would use for that check, but is rolled by the GM, who doesn’t reveal the result. Instead, the GM simply describes the information or effects determined by the check’s result. If you don’t know a secret check is happening (for instance, if the GM rolls a secret Fortitude save against a poison that you failed to notice), you can’t use any fortune or misfortune abilities (see the sidebar on page 449) on that check, but if a fortune or misfortune effect would apply automatically, the GM applies it to the secret check. If you know that the GM is attempting a secret check—as often happens with Recall Knowledge or Seek—you can usually activate fortune or misfortune abilities for that check. Just tell the GM, and they’ll apply the ability to the check.

The GM can choose to make any check secret, even if it’s not usually rolled secretly. Conversely, the GM can let you roll any check yourself, even if that check would usually be secret. Some groups find it simpler to have players roll all secret checks and just try to avoid acting on any out-of-character knowledge, while others enjoy the mystery.

Damage

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In the midst of combat, you attempt checks to determine if you can damage your foe with weapons, spells, or alchemical concoctions. On a successful check, you hit and deal damage. Damage decreases a creature’s Hit Points on a 1-to-1 basis (so a creature that takes 6 damage loses 6 Hit Points). The full rules can be found in the Hit Points, Healing, and Dying section.

Damage is sometimes given as a fixed amount, but more often than not you’ll make a damage roll to determine how much damage you deal. A damage roll typically uses a number and type of dice determined by the weapon or unarmed attack used or the spell cast, and it is often enhanced by various modifiers, bonuses, and penalties. Like checks, a damage roll—especially a melee weapon damage roll—is often modified by a number of modifiers, penalties, and bonuses. When making a damage roll, you take the following steps, explained in detail below.
  1. Roll the dice indicated by the weapon, unarmed attack, or spell, and apply the modifiers, bonuses, and penalties that apply to the result of the roll.
  2. Determine the damage type.
  3. Apply the target’s immunities, weaknesses, and resistances to the damage.
  4. If any damage remains, reduce the target’s Hit Points by that amount.

Step 1: Roll the Damage Dice and Apply Modifiers, Bonuses, and Penalties

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Your weapon, unarmed attack, spell, or sometimes even a magic item determines what type of dice you roll for damage, and how many. For instance, if you’re using a normal longsword, you’ll roll 1d8. If you’re casting a 3rd-level fireball spell, you’ll roll 6d6. Sometimes, especially in the case of weapons, you’ll apply modifiers, bonuses, and penalties to the damage.

When you use melee weapons, unarmed attacks, and thrown ranged weapons, the most common modifier you’ll add to damage is your Strength ability modifier. Weapons with the propulsive trait sometimes add half your Strength modifier. You typically do not add an ability modifier to spell damage, damage from most ranged weapons, or damage from alchemical bombs and similar items.

As with checks, you might add circumstance, status, or item bonuses to your damage rolls, but if you have multiple bonuses of the same type, you add only the highest bonus of that type. Again like checks, you may also apply circumstance, status, item, and untyped penalties to the damage roll, and again you apply only the greatest penalty of a specific type but apply all untyped penalties together.

Use the formulas below.

Melee damage roll = damage die of weapon or unarmed attack + Strength modifier + bonuses + penalties

Ranged damage roll = damage die of weapon + Strength modifier for thrown weapons + bonuses + penalties

Spell (and similar effects) damage roll = damage die of the effect + bonuses + penalties

If the combined penalties on an attack would reduce the damage to 0 or below, you still deal 1 damage. Once your damage die is rolled, and you’ve applied any modifiers, bonuses, and penalties, move on to Step 2. Though sometimes there are special considerations, described below.

Increasing Damage

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In some cases, you increase the number of dice you roll when making weapon damage rolls. Magic weapons etched with the striking rune can add one or more weapon damage dice to your damage roll. These extra dice are the same die size as the weapon’s damage die. At certain levels, most characters gain the ability to deal extra damage from the weapon specialization class feature.

Persistent Damage

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Persistent damage is a condition that causes damage to recur beyond the original effect. Like normal damage, it can be doubled or halved based on the results of an attack roll or saving throw. Unlike with normal damage, when you are subject to persistent damage, you don't take it right away. Instead, you take the specified damage at the end of your turns, after which you attempt a DC 15 flat check to see if you recover from the persistent damage. See the Conditions Appendix on pages 618–623 for the complete rules regarding the persistent damage condition.

Doubling and Halving Damage

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Sometimes you’ll need to halve or double an amount of damage, such as when the outcome of your Strike is a critical hit, or when you succeed at a basic Reflex save against a spell. When this happens, you roll the damage normally, adding all the normal modifiers, bonuses, and penalties. Then you double or halve the amount as appropriate (rounding down if you halved it). The GM might allow you to roll the dice twice and double the modifiers, bonuses, and penalties instead of doubling the entire result, but this usually works best for single-target attacks or spells at low levels when you have a small number of damage dice to roll. Benefits you gain specifically from a critical hit, like the flaming weapon rune’s persistent fire damage or the extra damage die from the fatal weapon trait, aren’t doubled.

Step 2: Determine the Damage Type

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Once you’ve calculated how much damage you deal, you’ll need to determine the damage type. There are many types of damage and sometimes certain types are applied in different ways. The smack of a club deals bludgeoning damage. The stab of a spear deals piercing damage. The staccato crack of a lightning bolt spell deals electricity damage. Sometimes you might apply precision damage, dealing more damage for hitting a creature in a vulnerable spot or when the target is somehow vulnerable. The damage types are described in the Damage Types sidebar.

Step 3: Apply the Target's Immunities, Weaknesses, and Resistances

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Defenses against certain types of damage or effects are called immunities or resistances, while vulnerabilities are called weaknesses. Apply immunities first, then weaknesses, and resistances third. Immunity, weakness, or resistance to an alignment applies only to damage of that type, not to damage from an attacking creature of that alignment.

Immunity

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When you have immunity to a specific type of damage, you ignore all damage of that type. If you have immunity to a specific condition or type of effect, you can't be affected by that condition or any effect of that type. You can still be targeted by an ability that includes an effect or condition you are immune to; you just don't apply that particular effect or condition.

If you have immunity to effects with a certain trait (such as death effects, poison, or disease), you are unaffected by effects with that trait. Often, an effect has a trait and deals that type of damage (this is especially true in the case of energy damage types). In these cases, the immunity applies to the effect corresponding to the trait, not just the damage. However, some complex effects might have parts that affect you even if you're immune to one of the effect's traits; for instance, a spell that deals both fire and acid damage can still deal acid damage to you even if you're immune to fire.

Immunity to critical hits works a little differently. When a creature immune to critical hits is critically hit by a Strike or other attack that deals damage, it takes normal damage instead of double damage. This does not make it immune to any other critical success effects of other actions that have the attack trait (such as Grapple and Shove).

Another exception is immunity to nonlethal attacks. If you are immune to nonlethal attacks, you are immune to all damage from attacks with the nonlethal trait, no matter what other type the damage has. For instance, a stone golem has immunity to nonlethal attacks. This means that no matter how hard you hit it with your fist, you're not going to damage it—unless your fists don't have the nonlethal trait, such as if you're a monk.

Temporary Immunity

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Some effects grant you immunity to the same effect for a set amount of time. If an effect grants you temporary immunity, repeated applications of that effect don’t affect you for as long as the temporary immunity lasts. Unless the effect says it applies only to a certain creature’s ability, it doesn’t matter who created the effect. For example, the blindness spell says, “The target is temporarily immune to blindness for 1 minute.” If anyone casts blindness on that creature again before 1 minute passes, the spell has no effect.

Temporary immunity doesn’t prevent or end ongoing effects of the source of the temporary immunity. For instance, if an ability makes you frightened and you then gain temporary immunity to the ability, you don’t immediately lose the frightened condition due to the immunity you just gained—you simply don’t become frightened if you’re targeted by the ability again before the immunity ends.

Weaknesses

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If you have a weakness to a certain type of damage or damage from a certain source, that type of damage is extra effective against you. Whenever you would take that type of damage, increase the damage you take by the value of the weakness. For instance, if you are dealt 2d6 fire damage and have weakness 5 to fire, you take 2d6+5 fire damage.

If you have a weakness to something that doesn't normally deal damage, such as water, you take damage equal to the weakness value when touched or affected by it. If more than one weakness would apply to the same instance of damage, use only the highest applicable weakness value. This usually happens only when a monster is weak to both a type of physical damage and a given material.

Resistance

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If you have resistance to a type of damage, each time you take that type of damage, you reduce the amount of damage you take by the listed amount (to a minimum of 0 damage). Resistance can specify combinations of damage types or other traits. For instance, you might encounter a monster that’s resistant to non-magical bludgeoning damage, meaning it would take less damage from bludgeoning attacks that weren’t magical, but would take normal damage from your +1 mace (since it’s magical) or a non-magical spear (since it deals piercing damage). A resistance also might have an exception. For example, resistance 10 to physical damage (except silver) would reduce any physical damage by 10 unless that damage was dealt by a silver weapon.

If you have more than one type of resistance that would apply to the same instance of damage, use only the highest applicable resistance value.

It’s possible to have resistance to all damage. When an effect deals damage of multiple types and you have resistance to all damage, apply the resistance to each type of damage separately. If an attack would deal 7 slashing damage and 4 fire damage, resistance 5 to all damage would reduce the slashing damage to 2 and negate the fire damage entirely.

Step 4: If Damage Remains, Reduce the Target's Hit Points

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After applying the target’s immunities, resistances, and weaknesses to the damage, whatever damage is left reduces the target’s Hit Points on a 1-to-1 basis. More information about Hit Points can be found in the Hit Points, Healing, and Dying section.

Nonlethal Attacks

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You can make a nonlethal attack in an effort to knock someone out instead of killing them (see Knocked Out and Dying). Weapons with the nonlethal trait (including fists) do this automatically. You take a –2 circumstance penalty to the attack roll when you make a nonlethal attack using a weapon that doesn't have the nonlethal trait. You also take this penalty when making a lethal attack using a nonlethal weapon.

Spells and other effects with the nonlethal trait that reduce a creature to 0 Hit Points knock the creature out instead of killing them.

Conditions

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The results of various checks might apply conditions to you or, less often, an item. Conditions change your state of being in some way. You might be gripped with fear or made faster by a spell or magic item. One condition represents what happens when a creature successfully drains your blood or life essence, while others represent creatures’ attitudes toward you and how they interact with you.

Conditions are persistent; when you’re affected by a condition, its effects last until the stated duration ends, the condition is removed, or terms dictated in the condition cause it to end. The rules for conditions are summarized on page 454 and described in full on pages 618–623.

Effects

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Anything you do in the game has an effect. Many of these outcomes are easy to adjudicate during the game. If you tell the GM that you draw your sword, no check is needed, and the result is that your character is now holding a sword. Other times, the specific effect requires more detailed rules governing how your choice is resolved. Many spells, magic items, and feats create specific effects, and your character will be subject to effects caused by monsters, hazards, the environment, and other characters.

While a check might determine the overall impact or strength of an effect, a check is not always part of creating an effect. Casting a fly spell on yourself creates an effect that allows you to soar through the air, but casting the spell does not require a check. Conversely, using the Intimidate skill to Demoralize a foe does require a check, and your result on that check determines the effect’s outcome.

The following general rules are used to understand and apply effects.

Duration

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Most effects are discrete, creating an instantaneous effect when you let the GM know what actions you are going to use. Firing a bow, moving to a new space, or taking something out of your pack all resolve instantly. Other effects instead last for a certain duration. Once the duration has elapsed, the effect ends. The rules generally use the following conventions for durations, though spells have some special durations detailed on pages 304–305.

For an effect that lasts a number of rounds, the remaining duration decreases by 1 at the start of each turn of the creature that created the effect. This is common for beneficial effects that target you or your allies. Detrimental effects often last “until the end of the target’s next turn” or “through” a number of their turns (such as “through the target’s next 3 turns”), which means that the effect’s duration decreases at the end of the creature’s turn, rather than the start.

Instead of lasting a fixed number of rounds, a duration might end only when certain conditions are met (or cease to be true). If so, the effects last until those conditions are met.

Range and Reach

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Actions and other abilities that generate an effect typically work within a specified range or a reach. Most spells and abilities list a range—the maximum distance from the creature or object creating the effect in which the effect can occur.

Ranged and thrown weapons have a range increment. Attacks with such weapons work normally up to that range. Attacks against targets beyond that range take a –2 penalty, which worsens by 2 for every additional multiple of that range, to a maximum of a –10 penalty after five additional range increments. Attacks beyond this range are not possible. For example, if you are using a shortbow, your attacks take no penalty against a target up to 60 feet away, a –2 penalty if a target is over 60 and up to 120 feet away, a –4 if a target is over 120 and up to 180 feet away, and so on, up to a maximum distance of 360 feet.

Reach is how far you can physically reach with your body or a weapon. Melee Strikes rely on reach. Your reach also creates an area around your space where other creatures could trigger your reactions. Your reach is typically 5 feet, but weapons with the reach trait can extend this. Larger creatures can have greater reach; for instance, an ogre has a 10-foot reach. Unlike with measuring most distances, 10-foot reach can reach 2 squares diagonally. Reach greater than 10 feet is measured normally; 20-foot reach can reach 3 squares diagonally, 30-foot reach can reach 4, and so on.

Targets

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Some effects require you to choose specific targets. Targeting can be difficult or impossible if your chosen creature is undetected by you, if the creature doesn’t match restrictions on who you can target, or if some other ability prevents it from being targeted.

Some effects require a target to be willing. Only you can decide whether your PC is willing, and the GM decides whether an NPC is willing. Even if you or your character don’t know what the effect is, such as if your character is unconscious, you still decide if you’re willing.

Some effects target or require an ally, or otherwise refer to an ally. This must be someone on your side, often another PC, but it might be a bystander you are trying to protect. You are not your own ally. If it isn’t clear, the GM decides who counts as an ally or an enemy.

Areas

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Some effects occupy an area of a specified shape and size. An area effect always has a point of origin and extends out from that point. There are four types of areas: emanations, bursts, cones, and lines. When you’re playing in encounter mode and using a grid, areas are measured in the same way as movement (page 463), but areas’ distances are never reduced or affected by difficult terrain (page 475) or lesser cover (page 476). You can use the diagrams below as common reference templates for areas, rather than measuring squares each time. Many area effects describe only the effects on creatures in the area. The GM determines any effects to the environment and unattended objects.

Burst

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A burst effect issues forth in all directions from a single corner of a square within the range of the effect, spreading in all directions to a specified radius. For instance, when you cast fireball, it detonates at the corner of a square within 500 feet of you and creates a 20-foot burst, meaning it extends out 20 feet in every direction from the corner of the square you chose, affecting each creature whose space (or even one square of its space) is within the burst.

Cone

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A cone shoots out from you in a quarter circle on the grid. When you aim a cone, the first square of that cone must share an edge with your space if you’re aiming orthogonally, or it must touch a corner of your space if you’re aiming diagonally. If you’re Large or larger, the first square can run along the edge of any square of your space. You can’t aim a cone so that it overlaps your space. The cone extends out for a number of feet, widening as it goes, as shown in the Areas diagram. For instance, when a green dragon uses its breath weapon, it breathes a cone of poisonous gas that originates at the edge of one square of its space and affects a quarter-circle area 30 feet on each edge.

If you make a cone originate from someone or something else, follow these same rules, with the first square of the cone using an edge or corner of that creature or object’s space instead of your own.

Emanation

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An emanation issues forth from each side of your space, extending out to a specified number of feet in all directions. For instance, the bless spell's emanation radiates 5 or more feet outward from the caster. Because the sides of a creature's space are the starting point for the emanation, an emanation from a Large or larger creature affects a greater overall area than that of a Medium or smaller creature. Unless the text states otherwise, the creature creating an emanation effect chooses whether the creature at its center is affected.

Line

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A line shoots forth from you in a straight line in a direction of your choosing. The line affects each creature whose space it overlaps. Unless a line effect says otherwise, it is 5 feet wide. For example, the lightning bolt spell’s area is a 60-foot line that’s 5 feet wide.

Line of Effect

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When creating an effect, you usually need an unblocked path to the target of a spell, the origin point of an effect’s area, or the place where you create something with a spell or other ability. This is called a line of effect. You have line of effect unless a creature is entirely behind a solid physical barrier. Visibility doesn’t matter for line of effect, nor do portcullises and other barriers that aren’t totally solid. If you’re unsure whether a barrier is solid enough, usually a 1-foot-square gap is enough to maintain a line of effect, though the GM makes the final call.

In an area effect, creatures or targets must have line of effect to the point of origin to be affected. If there’s no line of effect between the origin of the area and the target, the effect doesn’t apply to that target. For example, if there’s a solid wall between the origin of a fireball and a creature that’s within the burst radius, the wall blocks the effect—that creature is unaffected by the fireball and doesn’t need to attempt a save against it. Likewise, any ongoing effects created by an ability with an area cease to affect anyone who moves outside of the line of effect.

Line of Sight

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Some effects require you to have line of sight to your target. As long as you can precisely sense the area (as described in Perception on page 464) and it is not blocked by a solid barrier (as described in Cover on pages 476–477), you have line of sight. An area of darkness prevents line of sight if you don’t have darkvision, but portcullises and other obstacles that aren’t totally solid do not. If you’re unsure whether a barrier is solid enough to block line of sight, usually a 1-foot-square gap is enough to maintain line of sight, though the GM makes the final call.

Afflictions

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Diseases and poisons are types of afflictions, as are curses and radiation. An affliction can infect a creature for a long time, progressing through different and often increasingly debilitating stages. The level of an affliction is the level of the monster, hazard, or item causing the affliction or, in the case of a spell, is listed in the affliction entry for that spell.

Format of Rules Elements

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Whether appearing in a spell, as an item, or within a creature’s stat block, afflictions appear in the following format.

Name and Traits

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The affliction’s name is given first, followed by its traits in parentheses—including the trait for the type of affliction (curse, disease, poison, and so forth). If the affliction needs to have a level specified, it follows the parentheses, followed by any unusual details, such as restrictions on removing the conditions imposed by an affliction.

Saving Throw

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When you’re first exposed to the affliction, you must attempt a saving throw against it. This first attempt to stave off the affliction is called the initial save. An affliction usually requires a Fortitude save, but the exact save and its DC are listed after the name and type of affliction. Spells that can poison you typically use the caster’s spell DC.

On a successful initial saving throw, you are unaffected by that exposure to the affliction. You do not need to attempt further saving throws against it unless you are exposed to the affliction again.

If you fail the initial saving throw, after the affliction’s onset period elapses (if applicable), you advance to stage 1 of the affliction and are subjected to the listed effect. On a critical failure, after its onset period (if applicable), you advance to stage 2 of the affliction and are subjected to that effect instead. The stages of an affliction are described below.

Onset

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Some afflictions have onset times. For these afflictions, once you fail your initial save, you don’t gain the effects for the first stage of the affliction until the onset time has elapsed. If this entry is absent, you gain the effects for the first stage (or the second stage on a critical failure) immediately upon failing the initial saving throw.

Maximum Duration

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If an affliction lasts only a limited amount of time, it lists a maximum duration. Once this duration passes, the affliction ends. Otherwise, the affliction lasts until you succeed at enough saves to recover, as described in Stages below.

Stages

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An affliction typically has multiple stages, each of which lists an effect followed by an interval in parentheses. When you reach a given stage of an affliction, you are subjected to the effects listed for that stage.

At the end of a stage’s listed interval, you must attempt a new saving throw. On a success, you reduce the stage by 1; on a critical success, you reduce the stage by 2. You are then subjected to the effects of the new stage. If the affliction’s stage is ever reduced below stage 1, the affliction ends and you don’t need to attempt further saves unless you’re exposed to the affliction again.

On a failure, the stage increases by 1; on a critical failure, the stage increases by 2. You are then subjected to the effects listed for the new stage. If a failure or critical failure would increase the stage beyond the highest listed stage, the affliction instead repeats the effects of the highest stage.

Conditions from Afflictions

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An affliction might give you conditions with a longer or shorter duration than the affliction. For instance, if an affliction causes you to be drained but has a maximum duration of 5 minutes, you remain drained even after the affliction ends, as is normal for the drained condition. Or, you might succeed at the flat check to remove persistent damage you took from an ongoing affliction, but you would still need to attempt saves to remove the affliction itself, and failing one might give you new persistent damage.

Multiple Exposures

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Multiple exposures to the same curse or disease currently affecting you have no effect. For a poison, however, failing the initial saving throw against a new exposure increases the stage by 1 (or by 2 if you critically fail) without affecting the maximum duration. This is true even if you’re within the poison’s onset period, though it doesn’t change the onset length.

Virulent Afflictions

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Afflictions with the virulent trait are harder to remove. You must succeed at two consecutive saves to reduce a virulent affliction’s stage by 1. A critical success reduces a virulent affliction’s stage by only 1 instead of by 2.

Counteracting

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Some effects try to counteract spells, afflictions, conditions, or other effects. Counteract checks compare the power of two forces and determine which defeats the other. Successfully counteracting an effect ends it unless noted otherwise.

When attempting a counteract check, add the relevant skill modifier or other appropriate modifier to your check against the target’s DC. If you’re counteracting an affliction, the DC is in the affliction’s stat block. If it’s a spell, use the caster’s DC. The GM can also calculate a DC based on the target effect’s level. For spells, the counteract check modifier is your spellcasting ability modifier plus your spellcasting proficiency bonus, plus any bonuses and penalties that specifically apply to counteract checks. What you can counteract depends on the check result and the target’s level. If an effect is a spell, its level is the counteract level. Otherwise, halve its level and round up to determine its counteract level. If an effect’s level is unclear and it came from a creature, halve and round up the creature’s level.

Critical Success Counteract the target if its counteract level is no more than 3 levels higher than your effect’s counteract level.
Success Counteract the target if its counteract level is no more than 1 level higher than your effect’s counteract level.
Failure Counteract the target if its counteract level is lower than your effect’s counteract level.
Critical Failure You fail to counteract the target.

Hit Points, Healing, and Dying

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All creatures and objects have Hit Points (HP). Your maximum Hit Point value represents your health, wherewithal, and heroic drive when you are in good health and rested. Your maximum Hit Points include the Hit Points you gain at 1st level from your ancestry and class, those you gain at higher levels from your class, and any you gain from other sources (like the Toughness general feat). When you take damage, you reduce your current Hit Points by a number equal to the damage dealt.

Some spells, items, and other effects, as well as simply resting, can heal living or undead creatures. When you are healed, you regain Hit Points equal to the amount healed, up to your maximum Hit Points.

Knocked Out and Dying

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Creatures cannot be reduced to fewer than 0 Hit Points. When most creatures reach 0 Hit Points, they die and are removed from play unless the attack was nonlethal, in which case they are instead knocked out for a significant amount of time (usually 1 minute or more). When undead and construct creatures reach 0 Hit Points, they are destroyed.

Player characters, their companions, and other significant characters and creatures don’t automatically die when they reach 0 Hit Points. Instead, they are knocked out and are at risk of death. At the GM’s discretion, villains, powerful monsters, special NPCs, and enemies with special abilities that are likely to bring them back to the fight (like ferocity, regeneration, or healing magic) can use these rules as well.

As a player character, when you are reduced to 0 Hit Points, you’re knocked out with the following effects:
  • You immediately move your initiative position to directly before the turn in which you were reduced to 0 HP.
  • You gain the dying 1 condition. If the effect that knocked you out was a critical success from the attacker or the result of your critical failure, you gain the dying 2 condition instead. If you have the wounded condition, increase your dying value by an amount equal to your wounded value. If the damage was dealt by a nonlethal attack or nonlethal effect, you don’t gain the dying condition; you are instead unconscious with 0 Hit Points.

Taking Damage while Dying

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If you take damage while you already have the dying condition, increase your dying condition value by 1, or by 2 if the damage came from an attacker’s critical hit or your own critical failure. If you have the wounded condition, remember to add the value of your wounded condition to your dying value.

Recovery Checks

Source Core Rulebook pg. 459 4.0
When you’re dying, at the start of each of your turns, you must attempt a flat check with a DC equal to 10 + your current dying value to see if you get better or worse. This is called a recovery check. The effects of this check are as follows.

Critical Success Your dying value is reduced by 2.
Success Your dying value is reduced by 1.
Failure Your dying value increases by 1.
Critical Failure Your dying value increases by 2.

Conditions Related to Death and Dying

Source Core Rulebook pg. 459 4.0
To understand the rules for getting knocked out and how dying works in the game, you’ll need some more information on the conditions used in those rules. Presented below are the rules for the dying, unconscious, wounded, and doomed conditions.

Dying

Source Core Rulebook pg. 459 4.0
You are bleeding out or otherwise at death’s door. While you have this condition, you are unconscious. Dying always includes a value. If this value ever reaches dying 4, you die. If you’re dying, you must attempt a recovery check at the start of your turn each round to determine whether you get better or worse.

If you lose the dying condition by succeeding at a recovery check and are still at 0 Hit Points, you remain unconscious, but you can wake up as described on page 460. You lose the dying condition automatically and wake up if you ever have 1 Hit Point or more. Anytime you lose the dying condition, you gain the wounded 1 condition, or increase your wounded value by 1 if you already have that condition.

Unconscious

Source Core Rulebook pg. 459 4.0
You’re sleeping, or you’ve been knocked out. You can’t act. You take a –4 status penalty to AC, Perception, and Reflex saves, and you have the blinded and flat-footed conditions. When you gain this condition, you fall prone and drop items you are wielding or holding unless the effect states otherwise or the GM determines you’re in a position in which you wouldn’t.

If you’re unconscious because you’re dying, you can’t wake up as long as you have 0 Hit Points. If you’re restored to 1 Hit Point or more via healing, you lose the dying and unconscious conditions and can act normally on your next turn.

If you are unconscious and at 0 Hit Points, but not dying, you naturally return to 1 Hit Point and awaken after sufficient time passes. The GM determines how long you remain unconscious, from a minimum of 10 minutes to several hours. If you receive healing during this time, you lose the unconscious condition and can act normally on your next turn.

If you’re unconscious and have more than 1 Hit Point (typically because you are asleep or unconscious due to an effect), you wake up in one of the following ways. Each causes you to lose the unconscious condition.

  • You take damage, provided the damage doesn’t reduce you to 0 Hit Points. (If the damage reduces you to 0 Hit Points, you remain unconscious and gain the dying condition as normal.)
  • You receive healing, other than the natural healing you get from resting.
  • Someone nudges or shakes you awake using an Interact action.
  • Loud noise is being made around you—though this isn’t automatic. At the start of your turn, you automatically attempt a Perception check against the noise’s DC (or the lowest DC if there is more than one noise), waking up if you succeed. This is often DC 5 for a battle, but if creatures are attempting to stay quiet around you, this Perception check uses their Stealth DC. Some magical effects make you sleep so deeply that they don’t allow you to attempt this Perception check.
  • If you are simply asleep, the GM decides you wake up either because you have had a restful night’s sleep or something disrupted that rest.

Wounded

Source Core Rulebook pg. 460 4.0
You have been seriously injured during a fight. Anytime you lose the dying condition, you become wounded 1 if you didn’t already have the wounded condition. If you already have the wounded condition, your wounded condition value instead increases by 1. If you gain the dying condition while wounded, increase the dying condition’s value by your wounded value. The wounded condition ends if someone successfully restores Hit Points to you with Treat Wounds, or if you are restored to full Hit Points and rest for 10 minutes.

Doomed

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Your life is ebbing away, bringing you ever closer to death. Some powerful spells and evil creatures can inflict the doomed condition on you. Doomed always includes a value. The maximum dying value at which you die is reduced by your doomed value. For example, if you were doomed 1, you would die upon reaching dying 3 instead of dying 4. If your maximum dying value is ever reduced to 0, you instantly die. When you die, you’re no longer doomed.

Your doomed value decreases by 1 each time you get a full night’s rest.

Death

Source Core Rulebook pg. 460 4.0
After you die, you can’t act or regain actions or be affected by spells that target creatures (unless they specifically target dead creatures), and for all other purposes you are an object. When you die, you are reduced to 0 Hit Points if you had a different amount, and you can’t be brought above 0 Hit Points as long as you remain dead. Some magic can bring creatures back to life, such as the resurrect ritual or the raise dead spell.

Heroic Recovery

Source Core Rulebook pg. 460 4.0
If you have at least 1 Hero Point (page 467), you can spend all of your remaining Hero Points at the start of your turn or when your dying value would increase. You lose the dying condition entirely and stabilize with 0 Hit Points. You don’t gain the wounded condition or increase its value from losing the dying condition in this way, but if you already had that condition, you don’t lose it or decrease its value.

Death Effects and Instant Death

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Some spells and abilities can kill you immediately or bring you closer to death without needing to reduce you to 0 Hit Points first. These abilities have the death trait and usually involve negative energy, the antithesis of life. If you are reduced to 0 Hit Points by a death effect, you are slain instantly without needing to reach dying 4. If an effect states it kills you outright, you die without having to reach dying 4 and without being reduced to 0 Hit Points.

Massive Damage

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You die instantly if you ever take damage equal to or greater than double your maximum Hit Points in one blow.

Temporary Hit Points

Source Core Rulebook pg. 461 4.0
Some spells or abilities give you temporary Hit Points. Track these separately from your current and maximum Hit Points; when you take damage, reduce your temporary Hit Points first. Most temporary Hit Points last for a limited duration. You can’t regain lost temporary Hit Points through healing, but you can gain more via other abilities. You can have temporary Hit Points from only one source at a time. If you gain temporary Hit Points when you already have some, choose whether to keep the amount you already have and their corresponding duration or to gain the new temporary Hit Points and their duration.

Items and Hit Points

Source Core Rulebook pg. 461 4.0
Items have Hit Points like creatures, but the rules for damaging them are different (page 272). An item has a Hardness statistic that reduces damage the item takes by that amount. The item then takes any damage left over. If an item is reduced to 0 HP, it’s destroyed. An item also has a Broken Threshold. If its HP are reduced to this amount or lower, it’s broken, meaning it can’t be used for its normal function and it doesn’t grant bonuses. Damaging an unattended item usually requires attacking it directly, and can be difficult due to that item’s Hardness and immunities. You usually can’t attack an attended object (one on a creature’s person).

Fast Healing and Regeneration

Source Core Rulebook pg. 461 4.0
A creature with fast healing or regeneration regains the listed amount of Hit Points each round at the beginning of its turn. A creature with regeneration has additional benefits. Its dying condition can't increase to a value that would kill it (this stops most creatures from going beyond dying 3) as long as its regeneration is active. If it takes damage of a type listed in the regeneration entry, its regeneration deactivates until the end of its next turn, including against the triggering damage.

Actions

Source Core Rulebook pg. 461 4.0
You affect the world around you primarily by using actions, which produce effects. Actions are most closely measured and restricted during the encounter mode of play, but even when it isn’t important for you to keep strict track of actions, they remain the way in which you interact with the game world. There are four types of actions: single actions, activities, reactions, and free actions.

Single actions can be completed in a very short time. They’re self-contained, and their effects are generated within the span of that single action. During an encounter, you get 3 actions at the beginning of your turn, which you can use as described on page 468.

Activities usually take longer and require using multiple actions, which must be spent in succession. Stride is a single action, but Sudden Charge is an activity in which you use both the Stride and Strike actions to generate its effect.

Reactions have triggers, which must be met for you to use the reaction. You can use a reaction anytime its trigger is met, whether it’s your turn or not. In an encounter, you get 1 reaction each round, which you can use as described on page 468. Outside of encounters, your use of reactions is more flexible and up to the GM. Reactions are usually triggered by other creatures or by events outside your control.

Free actions don’t cost you any of your actions per turn, nor do they cost your reaction. A free action with no trigger follows the same rules as a single action (except the action cost), and a free action with a trigger follows the same rules as a reaction (except the reaction cost).

Activities

Source Core Rulebook pg. 461 4.0
An activity typically involves using multiple actions to create an effect greater than you can produce with a single action, or combining multiple single actions to produce an effect that’s different from merely the sum of those actions. In some cases, usually when spellcasting, an activity can consist of only 1 action, 1 reaction, or even 1 free action.

An activity might cause you to use specific actions within it. You don’t have to spend additional actions to perform them—they’re already factored into the activity’s required actions. (See Subordinate Actions on page 462.)

You have to spend all the actions of an activity at once to gain its effects. In an encounter, this means you must complete it during your turn. If an activity gets interrupted or disrupted in an encounter (page 462), you lose all the actions you committed to it.

Exploration and Downtime Activities

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Outside of encounters, activities can take minutes, hours, or even days. These activities usually have the exploration or downtime trait to indicate they’re meant to be used during these modes of play. You can often do other things off and on as you carry out these activities, provided they aren’t significant activities of their own. For instance, if you’re Repairing an item, you might move around to stretch your legs or have a brief discussion—but you couldn’t also Decipher Writing at the same time.

If an activity that occurs outside of an encounter is interrupted or disrupted, as described in Disrupting Actions below, you usually lose the time you put in, but no additional time beyond that.

Actions with Triggers

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You can use free actions that have triggers and reactions only in response to certain events. Each such reaction and free action lists the trigger that must happen for you to perform it. When its trigger is satisfied—and only when it is satisfied—you can use the reaction or free action, though you don’t have to use the action if you don’t want to.

There are only a few basic reactions and free actions that all characters can use. You’re more likely to gain actions with triggers from your class, feats, and magic items.

Limitation on Triggers

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The triggers listed in the stat blocks of reactions and some free actions limit when you can use those actions. You can use only one action in response to a given trigger. For example, if you had a reaction and a free action that both had a trigger of “your turn begins,” you could use either of them at the start of your turn—but not both. If two triggers are similar, but not identical, the GM determines whether you can use one action in response to each or whether they’re effectively the same thing. Usually, this decision will be based on what’s happening in the narrative.

This limitation of one action per trigger is per creature; more than one creature can use a reaction or free action in response to a given trigger.

Other Actions

Source Core Rulebook pg. 462 4.0
Sometimes you need to attempt something not already covered by defined actions in the game. When this happens, the rules tell you how many actions you need to spend, as well as any traits your action might have. For example, a spell that lets you switch targets might say you can do so “by spending a single action, which has the concentrate trait.” Game masters can also use this approach when a character tries to do something that isn't covered in the rules.

Gaining and Losing Actions

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Conditions can change the number of actions you can use on your turn, or whether you can use actions at all. The slowed condition, for example, causes you to lose actions, while the quickened condition causes you to gain them. Conditions are detailed here. Whenever you lose a number of actions—whether from these conditions or in any other way—you choose which to lose if there's any difference between them. For instance, the haste spell makes you quickened, but it limits what you can use your extra action to do. If you lost an action while haste was active, you might want to lose the action from haste first, since it's more limited than your normal actions.

Some effects are even more restrictive. Certain abilities, instead of or in addition to changing the number of actions you can use, say specifically that you can't use reactions. The most restrictive form of reducing actions is when an effect states that you can't act: this means you can't use any actions, or even speak. When you can't act, you still regain your actions unless a condition (like stunned) prevents it.

Disrupting Actions

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Various abilities and conditions, such as an Attack of Opportunity, can disrupt an action. When an action is disrupted, you still use the actions or reactions you committed and you still expend any costs, but the action’s effects don’t occur. In the case of an activity, you usually lose all actions spent for the activity up through the end of that turn. For instance, if you began a Cast a Spell activity requiring 3 actions and the first action was disrupted, you lose all 3 actions that you committed to that activity.

The GM decides what effects a disruption causes beyond simply negating the effects that would have occurred from the disrupted action. For instance, a Leap disrupted midway wouldn’t transport you back to the start of your jump, and a disrupted item hand off might cause the item to fall to the ground instead of staying in the hand of the creature who was trying to give it away.

Movement

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Your movement and position determine how you can interact with the world. Moving around in exploration and downtime modes is relatively fluid and free form. Movement in encounter mode, by contrast, is governed by rules explained in Movement in Encounters. The rules below apply regardless of which mode you’re playing in.

Movement Types

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Creatures in Pathfinder soar through the clouds, scale sheer cliffs, and tunnel underfoot. Most creatures have a Speed, which is how fast they can move across the ground. Some abilities give you different ways to move, such as through the air or underground.

Each of these special movement types has its own Speed value. Many creatures have these Speeds naturally. The various types of movement are listed below. Since the Stride action can be used only with your normal Speed, moving using one of these movement types requires using a special action, and you can’t Step while using one of these movement types. Since Speed by itself refers to your land Speed, rules text concerning these special movement types specifies the movement types to which it applies. Even though Speeds aren’t checks, they can have item, circumstance, and status bonuses and penalties. These can’t reduce your Speeds below 5 feet unless stated otherwise.

Switching from one movement type to another requires ending your action that has the first movement type and using a new action that has the second movement type. For instance, if you Climbed 10 feet to the top of a cliff, you could then Stride forward 10 feet.

Speed

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Most characters and monsters have a speed statistic—also called land Speed—which indicates how quickly they can move across the ground. When you use the Stride action, you move a number of feet equal to your Speed. Numerous other abilities also allow you to move, from Crawling to Leaping, and most of them are based on your Speed in some way. Whenever a rule mentions your Speed without specifying a type, it’s referring to your land Speed.

Burrow Speed

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A burrow Speed lets you tunnel through the ground. You can use the Burrow action if you have a burrow Speed. Burrowing doesn’t normally leave behind a tunnel unless the ability specifically states that it does. Most creatures need to hold their breath when burrowing, and they may need tremorsense to navigate with any accuracy.

Climb Speed

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A climb Speed allows you to move up or down inclines and vertical surfaces. Instead of needing to attempt Athletics checks to Climb, you automatically succeed and move up to your climb Speed instead of the listed distance.

You might still have to attempt Athletics checks to Climb in hazardous conditions, to Climb extremely difficult surfaces, or to cross horizontal planes such as ceilings. You can also choose to roll an Athletics check to Climb rather than accept an automatic success in hopes of getting a critical success. Your climb Speed grants you a +4 circumstance bonus to Athletics checks to Climb.

If you have a climb Speed, you’re not flat-footed while climbing.

Fly Speed

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As long as you have a fly Speed, you can use the Fly and Arrest a Fall actions. You can also attempt to Maneuver in Flight if you’re trained in the Acrobatics skill.

Wind conditions can affect how you use the Fly action. In general, moving against the wind uses the same rules as moving through difficult terrain (or greater difficult terrain, if you’re also flying upward), and moving with the wind allows you to move 10 feet for every 5 feet of movement you spend (not cumulative with moving straight downward). For more information on spending movement, see Movement in Encounters.

Upward and downward movement are both relative to the gravity in your area; if you’re in a place with zero gravity, moving up or down is no different from moving horizontally.

Swim Speed

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With a swim Speed, you can propel yourself through the water with little impediment. Instead of attempting Athletics checks to Swim, you automatically succeed and move up to your swim Speed instead of the listed distance. Moving up or down is still moving through difficult terrain.

You might still have to attempt checks to Swim in hazardous conditions or to cross turbulent water. You can also choose to roll an Athletics check to Swim rather than accept an automatic success in hopes of getting a critical success. Your swim Speed grants you a +4 circumstance bonus to Athletics checks to Swim.

Having a swim Speed doesn’t necessarily mean you can breathe in water, so you might still have to hold your breath if you’re underwater to avoid drowning.

Falling

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When you fall more than 5 feet, you take bludgeoning damage equal to half the distance you fell when you land. Treat falls longer than 1,500 feet as though they were 1,500 feet (750 damage). If you take any damage from a fall, you land prone. You fall about 500 feet in the first round of falling and about 1,500 feet each round thereafter.

You can Grab an Edge as a reaction to reduce the damage from some falls. In addition, if you fall into water, snow, or another relatively soft substance, you can treat the fall as though it were 20 feet shorter, or 30 feet shorter if you intentionally dove in. The effective reduction can’t be greater than the depth (so when falling into 10-foot-deep water, you treat the fall as 10 feet shorter).

Falling on a Creature

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If you land on a creature, that creature must attempt a DC 15 Reflex save. Landing exactly on a creature after a long fall is almost impossible.

Critical Success The creature takes no damage.
Success The creature takes bludgeoning damage equal to one-quarter the falling damage you took.
Failure The creature takes bludgeoning damage equal to half the falling damage you took.
Critical Failure The creature takes the same amount of bludgeoning damage you took from the fall.

Falling Objects

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A dropped object takes damage just like a falling creature. If the object lands on a creature, that creature can attempt a Reflex save using the same rules as for a creature falling on a creature. Hazards and spells that involve falling objects, such as a rock slide, have their own rules about how they interact with creatures and the damage they deal.

Perception

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Your Perception measures your ability to notice things, search for what’s hidden, and tell whether something about a situation is suspicious. This statistic is frequently used for rolling initiative to determine who goes first in an encounter, and it’s also used for the Seek action.

The rules for rolling a Perception check are found on page 448. The rules below describe the effects of light and visibility on your specific senses to perceive the world, as well as the rules for sensing and locating creatures with Perception.

Light

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The amount of light in an area can affect how well you see things. There are three levels of light: bright light, dim light, and darkness. The rules in this book assume that all creatures are in bright light unless otherwise noted. A source of light lists the radius in which it sheds bright light, and it sheds dim light to double that radius.

Bright Light

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In bright light, such as sunlight, creatures and objects can be observed clearly by anyone with average vision or better. Some types of creatures are dazzled or blinded by bright light.

Dim Light

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Areas in shadow or lit by weak light sources are in dim light. Creatures and objects in dim light have the concealed condition, unless the seeker has darkvision or low-light vision (see Special Senses on page 465), or a precise sense other than vision.

Darkness

Source Core Rulebook pg. 464 4.0
A creature or object within darkness is hidden or undetected unless the seeker has darkvision or a precise sense other than vision (Special Senses are on page 465). A creature without darkvision or another means of perceiving in darkness has the blinded condition while in darkness, though it might be able to see illuminated areas beyond the darkness. If a creature can see into an illuminated area, it can observe creatures within that illuminated area normally. After being in darkness, sudden exposure to bright light might make you dazzled for a short time, as determined by the GM.

Senses

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The ways a creature can use Perception depend on what senses it has. The primary concepts you need to know for understanding senses are precise senses, imprecise senses, and the three states of detection a target can be in: observed, hidden, or undetected. Vision, hearing, and scent are three prominent senses, but they don’t have the same degree of acuity.

Precise Senses

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Average vision is a precise sense—a sense that can be used to perceive the world in nuanced detail. The only way to target a creature without having drawbacks is to use a precise sense. You can usually detect a creature automatically with a precise sense unless that creature is hiding or obscured by the environment, in which case you can use the Seek basic action to better detect the creature.

Imprecise Senses

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Hearing is an imprecise sense—it cannot detect the full range of detail that a precise sense can. You can usually sense a creature automatically with an imprecise sense, but it has the hidden condition instead of the observed condition. It might be undetected by you if it’s using Stealth or is in an environment that distorts the sense, such as a noisy room in the case of hearing. In those cases, you have to use the Seek basic action to detect the creature. At best, an imprecise sense can be used to make an undetected creature (or one you didn’t even know was there) merely hidden—it can’t make the creature observed.

Vague Senses

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A character also has many vague senses—ones that can alert you that something is there but aren’t useful for zeroing in on it to determine exactly what it is. The most useful of these for a typical character is the sense of smell. At best, a vague sense can be used to detect the presence of an unnoticed creature, making it undetected. Even then, the vague sense isn’t sufficient to make the creature hidden or observed.

When one creature might detect another, the GM almost always uses the most precise sense available.

Pathfinder’s rules assume that a given creature has vision as its only precise sense and hearing as its only imprecise sense. Some characters and creatures, however, have precise or imprecise senses that don’t match this assumption. For instance, a character with poor vision might treat that sense as imprecise, an animal with the scent ability can use its sense of smell as an imprecise sense, and a creature with echolocation or a similar ability can use hearing as a precise sense. Such senses are often given special names and appear as “echolocation (precise),” “scent (imprecise) 30 feet,” or the like.

Special Senses

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While a human might have a difficult time making creatures out in dim light, an elf can see those creatures just fine. And though elves have no problem seeing on a moonlit night, their vision cannot penetrate complete darkness, whereas a dwarf’s can.

Special senses grant greater awareness that allows a creature with these senses to either ignore or reduce the effects of the undetected, hidden, or concealed conditions (described in Detecting Creatures below) when it comes to situations that foil average vision. The following are a few examples of common special senses.

Darkvision and Greater Darkvision

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A creature with darkvision or greater darkvision can see perfectly well in areas of darkness and dim light, though such vision is in black and white only. Some forms of magical darkness, such as a 4th-level darkness spell, block normal darkvision. A creature with greater darkvision, however, can see through even these forms of magical darkness.

Low-Light Vision

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A creature with low-light vision can see in dim light as though it were bright light, so it ignores the concealed condition due to dim light.

Scent

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Scent involves sensing creatures or objects by smell, and is usually a vague sense. The range is listed in the ability, and it functions only if the creature or object being detected emits an aroma (for instance, incorporeal creatures usually do not exude an aroma).

If a creature emits a heavy aroma or is upwind, the GM can double or even triple the range of scent abilities used to detect that creature, and the GM can reduce the range if a creature is downwind.

Tremorsense

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Tremorsense allows a creature to feel the vibrations through a solid surface caused by movement. It is usually an imprecise sense with a limited range (listed in the ability). Tremorsense functions only if the detecting creature is on the same surface as the subject, and only if the subject is moving along (or burrowing through) the surface.

Detecting Creatures

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There are three conditions that measure the degree to which you can sense a creature: observed, hidden, and undetected. However, the concealed and invisible conditions can partially mask a creature, and the unnoticed condition indicates you have no idea a creature is around. In addition to the descriptions here, you can find these conditions in the Conditions Appendix on pages 618–623.

With the exception of invisible, these conditions are relative to the viewer—it's possible for a creature to be observed to you but hidden from your ally. When you're trying to target a creature that's hard to see or otherwise sense, various drawbacks apply. Most of these rules apply to objects you're trying to detect as well as creatures.

Typically, the GM tracks how well creatures detect each other, since neither party has perfect information. For example, you might think a creature is in the last place you sensed it, but it was able to Sneak away. Or you might think a creature can't see you in the dark, but it has darkvision.

You can attempt to avoid detection by using the Stealth skill to Avoid Notice, Hide, or Sneak, or by using Deception to Create a Diversion.

Observed

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In most circumstances, you can sense creatures without difficulty and target them normally. Creatures in this state are observed. Observing requires a precise sense, which for most creatures means sight, but see the Detecting with Other Senses sidebar (page 465) for advice regarding creatures that don’t use sight as their primary sense. If you can’t observe the creature, it’s either hidden, undetected, or unnoticed, and you’ll need to factor in the targeting restrictions. Even if a creature is observed, it might still be concealed.

Hidden

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A creature that’s hidden is only barely perceptible. You know what space a hidden creature occupies, but little else. Perhaps the creature just moved behind cover and successfully used the Hide action. Your target might be in a deep fogbank or behind a waterfall, where you can see some movement but can’t determine an exact location. Maybe you’ve been blinded or the creature is under the effects of invisibility, but you used the Seek basic action to determine its general location based on hearing alone. Regardless of the specifics, you’re flat-footed to a hidden creature.

When targeting a hidden creature, before you roll to determine your effect, you must attempt a DC 11 flat check. If you fail, you don’t affect the creature, though the actions you used are still expended—as well as any spell slots, costs, and other resources. You remain flat-footed to the creature, whether you successfully target it or not.

Undetected

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If a creature is undetected, you don’t know what space it occupies, you’re flat-footed to it, and you can’t easily target it. Using the Seek basic action can help you find an undetected creature, usually making it hidden from you instead of undetected. If a creature is undetected, that doesn’t necessarily mean you’re unaware of its presence—you might suspect an undetected creature is in the room with you, even though you’re unable to find its space. The unnoticed condition covers creatures you’re entirely unaware of.

Targeting an undetected creature is difficult. If you suspect there’s a creature around, you can pick a square and attempt an attack. This works like targeting a hidden creature, but the flat check and attack roll are both rolled in secret by the GM. The GM won’t tell you why you missed—whether it was due to failing the flat check, rolling an insufficient attack roll, or choosing the wrong square. The GM might allow you to try targeting an undetected creature with some spells or other abilities in a similar fashion. Undetected creatures are subject to area effects normally.

For instance, suppose an enemy elf wizard cast invisibility and then Sneaked away. You suspect that with the elf’s Speed of 30 feet, they probably moved 15 feet toward an open door. You move up and attack a space 15 feet from where the elf started and directly on the path to the door. The GM secretly rolls an attack roll and flat check, but they know that you were not quite correct—the elf was actually in the adjacent space! The GM tells you that you missed, so you decide to make your next attack on the adjacent space, just in case. This time, it’s the right space, and the GM’s secret attack roll and flat check both succeed, so you hit!

Unnoticed

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If you have no idea a creature is even present, that creature is unnoticed by you. A creature that is undetected might also be unnoticed. This condition usually matters for abilities that can be used only against targets totally unaware of your presence.

Concealment and Invisibility

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The concealed and invisible conditions reflect certain circumstances that can make a creature harder to see.

Concealed

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This condition protects a creature if it’s in mist, within dim light, or amid something else that obscures sight but does not provide a physical barrier to effects. An effect or type of terrain that describes an area of concealment makes all creatures within it concealed.

When you target a creature that’s concealed from you, you must attempt a DC 5 flat check before you roll to determine your effect. If you fail, you don’t affect the target. The concealed condition doesn’t change which of the main categories of detection apply to the creature. A creature in a light fog bank is still observed even though it’s concealed.

Invisible

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A creature with the invisible condition (by way of an invisibility spell or invisibility potion, for example) is automatically undetected to any creatures relying on sight as their only precise sense. Precise senses other than sight ignore the invisible condition.

You can use the Seek basic action to attempt to figure out an invisible creature’s location, making it instead only hidden from you. This lasts until the invisible creature successfully uses Sneak to become undetected again. If you’re already observing a creature when it becomes invisible, it starts out hidden, since you know where it was when it became invisible, though it can then Sneak to become undetected.

Other effects might make an invisible creature hidden or even observed but concealed. For instance, if you were tracking an invisible creature’s footprints through the snow, the footprints would make it hidden. Similarly, throwing a net over an invisible creature would make it observed but concealed for as long as the net is on the creature.

Hero Points

Source Core Rulebook pg. 467 4.0
Your heroic deeds earn you Hero Points, which grant you good fortune or let you recover from the brink of death. Unlike most aspects of your character, which persist over the long term, Hero Points last for only a single session.

The GM is in charge of awarding Hero Points. Usually, each character gets 1 Hero Point at the start of a session and can gain more later by performing heroic deeds—something selfless, daring, or beyond normal expectations. You can have a maximum of 3 Hero Points at a time, and you lose any remaining Hero Points at the end of a session.

You can spend your Hero Points in one of two ways. Neither of these is an action, and you can spend Hero Points even if you aren't able to act. You can spend a Hero Point on behalf of your familiar or animal companion.
  • Spend 1 Hero Point to reroll a check. You must use the second result. This is a fortune effect (which means you can't use more than 1 Hero Point on a check).
  • Spend all your Hero Points (minimum 1) to avoid death. You can do this when your dying condition would increase. You lose the dying condition entirely and stabilize with 0 Hit Points. You don't gain the wounded condition or increase its value from losing the dying condition in this way, but if you already had that condition, you don't lose it or decrease its value.

Describing Heroic Deeds

Source Core Rulebook pg. 467 4.0
Because spending Hero Points reflects heroic deeds or tasks that surpass normal expectations, if you spend a Hero Point, you should describe the deed or task your character accomplishes with it to the other players.

Your character’s deed might invoke a lesson learned in a past adventure, could be spurred by a determination to save someone else, or might depend on an item that ended up on their person due to a previous exploit. If you don’t want to describe the deed or don’t have any strong ideas about how to do so, ask the GM to come up with something for you. This can be a collaborative process, too. The GM might remind you of a long-forgotten event in the campaign, and all you have to do is fill in how that event comes to mind just at the right time, motivating you to push past your limits.