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GM Core / Chapter 4: Subsystems

Hexploration

Source GM Core pg. 206 2.0
Few activities epitomize adventure as much as pure exploration through an unknown wilderness. Leaving the city streets and trade roads behind and striking out into the unknown can test the mettle of the most experienced adventurers, but such efforts reward those seeking fantastical sites, natural resources, and unforeseen opportunities.

While you can represent long, heroic journeys using normal exploration, if you want something more detailed, you can use the hexploration subsystem instead. This is a method where the overland map is divided into individual hexagonal sections of territory. During their exploration, the PCs travel through and explore individual hexes, finding interesting sites, secrets, resources, and dangers.

The pace of travel is measured in days rather than hours or minutes. This means choosing hexploration activities are more akin to choosing downtime activities than exploration activities. Each day, the PCs explore or travel through a region of the wilderness measured in hexes on a map to survey, discover resources, forage, find sites, and reconnoiter potential foes and allies.

Hexploration is ideal for sandbox-style campaigns, where the players are at liberty to set the course of their own adventure. The GM populates a region with interesting locations and situations that the players explore in any order they see fit.

Designing the Map

Source GM Core pg. 206 2.0
The best way to map the area is with a hex grid. Each hex represents a discreet area 12 miles from corner to corner, which can be traveled across and explored in about 1 day even by slower-moving groups. Hexes track the distance the party travels while exploring and define the bounds of certain types of terrain.

When designing your hex map, it's best to have each hex represent one primary terrain type. This doesn't mean that's the only feature of the land in this hex, but it is the predominant type and represents the challenges of traveling across and exploring that hex. You can also give your hex other elements: a river or a road might snake through the area, or it could contain a castle, cave, village, fort, or some other type of encounter setting. You can quickly draw your map using just a few colors, some basic symbols, and letters or numbers for reference.

But this is only the start. This detailed map is your GM map, holding all the secrets for the PCs to discover. Give the players a blank map that they can fill in as they explore the wilderness hex by hex. The more they explore, the more their map will look like yours.

Populating Hexes

Source GM Core pg. 206 2.0
When populating a hexploration map, keep in mind that you have little control over which areas the players choose to explore first—or if they’ll explore those areas at all. Because hexploration leads to nonlinear, player-guided play, consider providing hooks within encounters and sites for them to explore in several directions from their starting point. You can provide some direction by presenting jobs like exploring a site on behalf of an NPC, escorting travelers, delivering goods, or scouting a region for a local noble. This typically leads to a set encounter (see below).

Set Encounters

Source GM Core pg. 206 2.0
Even a sandbox adventure has a story or is the setting of multiple stories. Set encounters, be they just a simple encounter or an entire adventuring site, can serve as important beats in the story behind the PCs’ exploration. These are typically the points on the hex maps the PCs are searching for, and the discovery of one set encounter will often incorporate story points that lead to the next.

Random Encounters

Source GM Core pg. 206 2.0
You can instill additional danger into your hexploration by including random encounters, whether they take the form of interesting features, natural hazards, or creatures native to the terrain. It can help to create a series of short lists in advance, each including a mix of three types of encounters: harmless, hazards, and creature encounters. Then create tables to randomize the results, or simply pick whichever encounter you think would work best for your hexploration narrative when these encounters occur (as described in Random Encounters on page 209). It's often easier to create a list by terrain rather than for each hex. The forest hexes could have their own random encounter list while the plains beyond have a different list, possibly with some overlap.

A harmless encounter is just that: the party is in no danger from it. Harmless encounters can be opportunities to flesh out the world with interesting bits of set-dressing, like a shrine on the side of the road dedicated to a minor god, opportunities for the party to interact with other travelers, or simply interesting or noteworthy moments on the road, like a distant and dazzling electrical storm.

Hazard encounters can include those located in the Hazards section on pages 98–108, primarily the environmental hazards and haunts. You can also create your own hazards (page 109).

Creature encounters can use the creatures found in Monster Core, or you can create your own using the rules found in Building Creatures on page 112.

Plan your hazard and monster encounters with a degree of flexibility so you can tailor them to the PCs' current level, perhaps by creating a lower-level encounter and including notes on how to scale it up. Alternatively, if you want to run a more challenging or open-world hexploration, don't adapt to your players at all. Make a variety of encounters, some of which are so powerful that the correct tactic is to flee. You can even create a chase to make the escape exciting (see Chases on page 192).

Terrain

Source GM Core pg. 207 2.0
While each hex should have a predominant terrain type, your terrain can come alive using the info in the Environments section on pages 90–97. A hex might also include a river or road. These can cut through the terrain, making it easier for the PCs to travel through the hex, so long as they follow the path. Additionally, each hex might have special features like resources and secrets (see the Types of Terrain sidebar on page 209).

Generating Random Hex Maps

Source GM Core pg. 207 2.0
If you’d like to create your map randomly, begin by selecting a hex on a blank map as the starting point. Then decide the type of terrain for that starting point or roll it on the Random Terrain Type table on page 208. From that point onward, let the players decide which direction they travel. If they enter an unexplored hex, generate that hex by rolling 1d20 on the Random Terrain Type and Random Terrain Feature tables to determine a type and element for that hex. Apply common sense when producing terrain in this way. Unless magic is involved, it is unlikely a patch of arctic ice would appear in the heart of a desert—though figuring out a way for that to occur could lead to an interesting encounter or subplot later on.

Running Hexploration

Source GM Core pg. 207 2.0
Once you have your hexploration map ready, it's time for the PCs to start exploring! Each day, the PCs decide how they plan on exploring, either learning more about their current hex or traversing a new hex. They do this by declaring one or more hexploration activities for the day. These activities take two forms: group or individual. The number of hexploration activities a group can accomplish each day is based on the Speed of their slowest member. If a group is willing to split up, faster members can perform more hexploration activities based on their own Speed, but such a decision may be deadly given the threat of random encounters. A group moving at a Speed of 10 feet or less is so slow it can't even traverse an open hex in a single day; it takes such a group 2 days for each hexploration activity.

This rate assumes the PCs are taking time to camp and rest at healthy intervals. When a new day of hexploration begins, the group can decide to take a forced march as long as no one in the group is fatigued. Doing so allows them to gain an extra Travel activity (or perform a full Travel activity each day if their Speed is 10 feet or less), but this is the only activity they can perform that day. A character can participate in a forced march safely for a number of days equal to the character's Constitution modifier (minimum 1 day). Any additional days of forced march make the character fatigued until they spend an entire day of downtime resting.

Table 3–4: Random Terrain Type

1d20 Result
1–3Plains
4–5Desert
6–7Aquatic (lake, sea, or ocean)
8–9Mountain
10–11Forest
12Swamp
13Arctic
14–20Match the previous hex

Table 3–5: Random Terrain Feature

1d20Result
1–3Landmark A feature of some significance that distinguishes the hex as noteworthy.
4–6Secret The hex contains a secret the party uncovers upon exploring the hex.
7–9Resource The hex contains some valuable resource appropriate to the terrain.
10–20Standard A standard representation of the terrain type.

Table 3–6: Hexploration Activities Per Day

SpeedActivities per Day
10 feet or less1/2
15–25 feet1
30–40 feet2
45–55 feet3
60 feet or more4

Group Activities

Source GM Core pg. 208 2.0
Group activities require the entire party to work together in order to be effective; these activities each count as one of the day’s hexploration activities for the whole group. For instance, if the group had 2 hexploration activities per day and decided to Travel and Reconnoiter, no one would have any additional hexploration activities that day. There are two group activities: Travel and Reconnoiter.

Travel

Move 
Source Gamemastery Guide pg. 172
You progress toward moving into an adjacent hex. In open terrain, like a plain, using 1 Travel activity allows you to move from one hex to an adjacent hex. Traversing a hex with difficult terrain (such as a typical forest or desert) requires 2 Travel activities, and hexes of greater difficult terrain (such as a steep mountain or typical swamp) require 3 Travel activities to traverse. Traveling along a road uses a terrain type one step better than the surrounding terrain. For example, if you are traveling on a road over a mountain pass, the terrain is difficult terrain instead of greater difficult terrain.

The Travel activity assumes you are walking overland. If you are flying or traveling on water, most hexes are open terrain, though there are exceptions. Flying into storms or high winds count as difficult or greater difficult terrain. Traveling down a river is open terrain, but traveling upriver is difficult or greater difficult terrain.

Reconnoiter

Concentrate 
Source Gamemastery Guide pg. 173
You spend time surveying and exploring a specific area, getting the lay of the land and looking for unusual features and specific sites. Reconnoitering a single hex takes a number of hexploration activities equal to the number of Travel activities necessary to traverse the hex—1 for open terrain, 2 for difficult terrain, and 3 for greater difficult terrain. Traveling on roads doesn’t lessen the time required to Reconnoiter. Once the hex has been Reconnoitered, you can Map the Area to reduce your chance of getting lost in that hex (see below). You automatically find any special feature that doesn’t require a check to find, and you attempt the appropriate checks to find hidden special features.

For instance, if you were looking for an obvious rock formation among some hills, you would spend 2 hexploration activities to Reconnoiter the hex, and you’d find the rock formation. But if you were looking for a hidden tengu monastery somewhere in some deep forests, after spending 2 activities to Reconnoiter the forest hex, you would have to succeed at a Perception check as part of your Reconnoiter activity to find the monastery.

Individual Activities

Source GM Core pg. 208 2.0
Not all hexploration activities need to be accomplished as a group. In place of using a hexploration activity to Travel or Reconnoiter, each individual group member can instead perform one of these individual activities.

Fortify Camp

Source Gamemastery Guide pg. 173
You can spend time fortifying your camp for defense with a successful Crafting check (typically at a trained or expert DC). Anyone keeping watch or defending the camp gains a +2 circumstance bonus to initiative rolls and Perception checks to Seek creatures attempting to sneak up on the camp.

Map the Area

Concentrate 
Source Gamemastery Guide pg. 173
As long as your group has successfully Reconnoitered the hex, you can use this activity to create an accurate map of the hex with a successful Survival check (typically at a trained or expert DC). When you have an accurate map of the hex, the DC of any check to navigate that hex is reduced by 2.

Existing Activities

Source GM Core pg. 208 2.0
Characters can use the Subsist downtime activity, which follows the same rules but assumes they’re using it after 8 hours or less of exploration. Any skill feats or other abilities that apply to Subsist normally still apply here. In general, the various exploration activities found in the sidebar on pages 438-439 of Player Core (except Hustle) can be used as individual hexploration activities, as can skill actions in Chapter 4 of Player Core, at the GM’s discretion.

Random Encounters

Source GM Core pg. 209 2.0
When exploring, there is always a chance the PCs will stumble upon random encounters, depending on the terrain. At the start of each day of hexploration, roll a flat check and consult the appropriate terrain type on the Random Encounter Chance table. If the flat check is a success, the PCs have a random encounter, and on a critical success, they have two random encounters. Roll on the Random Encounter Type table to determine the type of encounter. Once you know the type of the encounter, either choose from the list you made for that region or choose your own.

Table 3–7: Random Encounter Chance

Terrain TypeFlat Check DC*
Aquatic17
Arctic17
Desert17
Forest14
Mountain16
Plains12
Swamp14
* On a road or river, decrease the DC by 2. If PCs are flying, increase the DC by 3, but choose a hazard or monster that is relevant to flying PCs.

Table 3–8: Random Encounter Type

1d10Encounter
1–5Harmless
6–7Hazard
8–10Creature

Switching out of Hexploration

Source GM Core pg. 209 2.0
Most short encounters do not affect the number of hexploration activities that the PCs can perform during the day, but when the PCs take on multiple encounters or engage in activities that take hours rather than minutes, you’ll want to deduct the time from their available hexploration activities. For the story’s sake, it’s best to think of hexploration activities as the various things that the PCs have time to do in the daylight hours. For instance, maybe the group spends 2 of their 3 hexploration activities Reconnoitering a hex, finding a tengu monastery, and learning that it is a sprawling complex underneath a small, wooded hill. You might decide that the PCs found it in the evening, and they have the choice between making a foray into the complex late in the day or pursuing some individual activities, camping for the night, and starting off fresh in the morning.