While some battles take place in open terrain, some battlefields contain additional terrain features. Relatively common battlefield terrain features are detailed below; some of the scripted war encounters in the Adventure Path feature other, specific terrain features.

Darkness or Heavy Fog: All armies become concealed, and distant armies become undetected. Armies in these conditions take a –4 circumstance penalty on Scouting checks. Armies with darkvision ignore the terrain effects of darkness.

Difficult Terrain: A war encounter that takes place in rugged mountains, swampland, or dense forests are examples of difficult battlefield terrain. Armies take a –2 circumstance penalty on Maneuver checks in difficult terrain.

Dim Light, Light Fog, or Rain: Armies in these conditions gain a +1 circumstance bonus on Maneuver checks and take a –2 circumstance penalty on Scouting checks. Distant armies become concealed. Armies with low-light vision or darkvision ignore the terrain effects of dim light.

Wind: Ranged Strikes take a –1 circumstance penalty in strong wind, or a –2 circumstance penalty in windstorms. The penalty for a ranged Strike on a distant army is doubled to –10 (this penalty stacks with the standard penalty to ranged Strikes in wind).