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Chapter 9: Playing the Game / General Rules / Specific Checks

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 Bonuses for Perception - Common Items
ItemBonusLevelCategoryConsumable?Note
Magnifying Glass+13Adventuring GearNoPerception checks to notice minute details of documents, fabric, and the like
Magnifying Scope+13ScopesNoVisual Perception checks to Seek creatures through the scope
Eye Slash (Greater)+14TattoosNoVisual Perception checks
Spyglass (Fine)+14Adventuring GearNoPerception checks to notice details at a distance
Mirror Goggles (Lesser)+15Other Worn ItemsNoVisual Perception checks
Goggles of Night+15Other Worn ItemsNoPerception checks involving sight
Darkvision 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).
Eye of the Unseen+18Assistive ItemsNoVisual Perception checks
Clarity Goggles (Lesser)+18Other Worn ItemsNoVisual Perception checks
Codex of Unimpeded Sight (Greater)+112GrimoiresNoPerception checks to Seek
Serene Mutagen (Lesser)+11Alchemical ElixirsYes
Drakeheart Mutagen (Lesser)+11Alchemical ElixirsYes
Eagle-Eye Elixir (Lesser)+11Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
Diplomat's Charcuterie+13Alchemical FoodYesDiplomacy checks to Make an Impression
Eye of the Unseen+28Assistive ItemsNoVisual Perception checks
Magnifying Scope (Greater)+29ScopesNoVisual Perception checks to Seek creatures through the scope
Eye Slash (Major)+29TattoosNoVisual Perception checks
Jann's Prism+29Held ItemsNovisual Perception checks
Eyes of the Eagle+29Other Worn ItemsNoPerception checks that involve sight
Sun Sight+210TattoosNoVisual Perception checks
Mirror Goggles (Moderate)+211Other Worn ItemsNoVisual Perception checks
Goggles of Night (Greater)+211Other Worn ItemsNoPerception checks involving sight
Spectacles of Inquiry+212Other Worn ItemsNo
Clarity Goggles (Moderate)+213Other Worn ItemsNoVisual Perception checks
Scope of Truth+213ScopesNoPerception checks made to Seek in areas you can see through the scope
Darkvision 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).
Amulet of the Third Eye+217Other Worn ItemsNo
Drakeheart Mutagen (Moderate)+23Alchemical ElixirsYes
Serene Mutagen (Moderate)+23Alchemical ElixirsYes
Zerk+24DrugsYesPerception rolls for initiative
Eagle-Eye Elixir (Moderate)+25Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
Magnifying Scope (Major)+317ScopesNoVisual Perception checks to Seek creatures through the scope
Eye Slash (True)+317TattoosNoVisual Perception checks
Mirror Goggles (Greater)+318Other Worn ItemsNoVisual Perception checks
Goggles of Night (Major)+318Other Worn ItemsNoPerception checks involving sight
Clarity Goggles (Greater)+319Other Worn ItemsNoVisual Perception checks
Third Eye+319Other Worn ItemsNo
Eagle-Eye Elixir (Greater)+310Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
Serene Mutagen (Greater)+311Alchemical ElixirsYes
Drakeheart Mutagen (Greater)+311Alchemical ElixirsYes
Eagle-Eye Elixir (Major)+316Alchemical ElixirsYesPerception checks that is greater when attempting to find secret doors and traps.
Drakeheart Mutagen (Major)+417Alchemical ElixirsYes
Serene Mutagen (Major)+417Alchemical ElixirsYes
Item Bonuses for Perception - Uncommon/Rare/Unique Items
ItemBonusLevelCategoryConsumable?Note
Vestige Lenses+13Alchemical OtherNoPerception checks to Seek any alchemical vapors
Skinsaw Mask+13Other Worn ItemsNoPerception checks to Seek frightened creatures
Skinsaw Mask+13Other Worn ItemsNoSeek frightened creatures
Sleuth's Pipe+13Relic SeedsNoPerception checks to Sense Motive
Stalk Goggles (Greater)+13Other Worn ItemsNoPerception checks involving sight
Seer's Flute+14CodaNowhile playing the flute
Ring of the Tiger +15Other Worn ItemsNoPerception checks made in outdoor wilderness areas
Stag's Helm+16Other Worn ItemsNo
Umbral Wings+18Other Worn ItemsNoChecks to Seek
Seer's Flute (Greater)+18CodaNowhile playing the flute
Diviner's Nose Chain+19Other Worn ItemsNoSeek or Sense Motive
Drazmorg's Staff of All-Sight+110StavesNoVisual Perception checks
Skeptic's Elixir (Lesser)+11Alchemical ElixirsYesPerception checks and Perception DCs to notice falsehoods, whether they're spoken lies or written deceit
Grim Ring+25Other Worn ItemsNoSecret Perception checks against undead in the area that are hiding or disguised
Spiritsight Ring+26Other Worn ItemsNoSeek to find hidden or undetected incorporeal creatures within 30 feet of you
Stalk Goggles (Major)+28Other Worn ItemsNoPerception checks involving sight
Starless Scope+29Held ItemsNoPerception checks made to observe the skies
Aeon Stone (Cymophane Cabochon)+29Other Worn ItemsNo
Ring of the Tiger (Greater)+210Other Worn ItemsNoPerception checks made in outdoor wilderness areas
Spectral Opera Glasses+211Held ItemsNo
Bring Me Near+212Held ItemsNoVisual Perception checks
Seer's Flute (Major)+212CodaNowhile playing the flute
Exploration Lens (Searching)+214Held ItemsNoPerception checks to spot hidden doors and concealed hazards while Searching
The Big Sky+220The Deck of DestinyNoPerception checks made while flying outside during the day (+3 at 17th level)
The Trumpet+220The Deck of DestinyNoinitiative checks made with hearing-based Perception checks
The Owl+220The Deck of DestinyNoPerception checks made to Sense Motive (+3 at 17th level).
The Inquisitor+220The Deck of DestinyNoPerception checks to Sense Motive against creatures higher level than you (+3 at 17th level).
The Unicorn+220The Deck of DestinyNoPerception checks to Seek (+3 at 17th level).
The Winged Serpent+220The Deck of DestinyNosight-based Perception checks for initiative (+3 at 17th level).
Skeptic's Elixir (Moderate)+26Alchemical ElixirsYesPerception checks and Perception DCs to notice falsehoods, whether they're spoken lies or written deceit
Dragonfly Potion+212PotionsYesVisual Perception checks
Robe of Eyes+317Other Worn ItemsNo
Void Mirror+320ArtifactsNoPerception checks made while using the mirror
Skeptic'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.