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Archives of Nethys

Archives of Nethys

Pathfinder RPG (1st Edition) Pathfinder RPG (2nd Edition) Starfinder RPG

Rules Index | GM Screen | Player's Guide
GM Core / Chapter 2: Building Games / Environment

Underground

Source GM Core pg. 94 2.0
Underground environments consist of caves and natural underground areas. Artificial dungeons and ruins combine underground features with urban features like stairs and walls. Deep underground vaults have some of the same terrain features as mountains, such as chasms and cliffs. The most common disasters underground are collapses.

Dungeons

Dungeon environments, which include both ruins and contemporary buildings constructed in the wilderness, are a fairly common venue for adventures. As an environment, they combine urban features like doors and buildings (page 92) with features from an underground environment, and occasionally components from other environments. While underground dungeons are particularly common, you might also consider setting your adventure in a ruin reclaimed by the forest, with giant trees spreading their roots through the walls, or a ruin deep in a swamp, with bogs covering access to some of the ruin’s hidden secrets.

Floors

Source GM Core pg. 94 2.0
Natural underground environments rarely have flat floors, instead featuring abrupt changes in elevation that result in difficult terrain, uneven ground, and inclines.

Ledges

Source GM Core pg. 94 2.0
Ledges are narrow surfaces that overlook a lower area or provide the only means to move along the edge of a chasm. Moving across a narrow ledge requires using Acrobatics to Balance.

Rubble

Source GM Core pg. 94 2.0
Caverns can be covered in rubble, which is difficult terrain. Deep or pervasive rubble is also uneven ground.

Stalagmites and Stalactites

Source GM Core pg. 94 2.0
Stalagmites are tapering columns that rise from the floor of a cave. Areas filled with stalagmites are greater difficult terrain, and especially large stalagmites have to be sidestepped or Climbed. Stalagmites can be sharp enough they can be used as hazardous terrain in some circumstances, as can stalactites (icicle-shaped formations that hang from the roof of a cave) if they’re knocked loose from a ceiling or overhang.

Walls

Source GM Core pg. 94 2.0
Natural cave walls are rough and uneven, with nooks, crannies, and ledges. Since most caves are formed by water, cave walls are often damp, making them even more difficult to Climb.