Rubble, undergrowth, shallow bogs, steep stairs, and all sorts of other impediments are difficult terrain that hampers movement.
- Costs 1 Extra Square: Each square of difficult terrain you enter costs 1 extra square of movement. You do not incur additional movement cost for leaving a square of difficult terrain.
- Large, Huge, and Gargantuan Creatures: If such a creature enters two or more squares with different types of terrain, count that square of movement according to the most difficult terrain. Count only squares it is entering for the first time, not squares it already occupies.
- Ending Movement: If you don’t have enough movement remaining to enter a square of difficult terrain, you can’t enter it.
- Flying: Creatures are not hampered by difficult terrain when flying.
- Terrain Walk: Some creatures have a special ability to ignore difficult terrain in specific kinds of environments. For example, dryads have forest walk, which allows them to ignore difficult terrain in forests.
Because difficult terrain costs 1 extra square of movement to enter, you can’t normally shift into a square of difficult terrain. On the other hand, if a power lets you shift 2 or more, you can shift into a square of difficult terrain.