All provinces in the game have a set of terrain tags. Terrain influences provinces in many different ways:

• It influences the size of the population in the province as well as available resources and recruitment points.
• It determines the frequency and types of magic sites that can spawn.
• It determines what independents spawn, as well the type of province defense and independent recruits that players may buy a
• It affects the movement cost of units moving through the province.
• It can influence units in combat, adding penalties to those not adapted to the environment.

Certain terrain applies penalties to units in combat.