Fire

Fire is often used as an obstacle as it is generally too hot to safely pass through and is very mobile creating a believably dynamic obstacle course for the player to travel through. A good example of this is when escaping from the burning barn in Call of Juarez, burning beams will fall and block your path as you scramble past, increasing the feeling of desperation as you hurriedly try to find an exit. Fire is also a rather effective weapon in Far Cry 2, where the player can burn the foliage around an enemy encampment in the hope of flushing out infantry or setting of hidden ammunition dumps as a secondary effect. Lesser effects of fire include signalling to the player, a burning car in the GTA series spectacularly informs the player that their vehicle will soon explode.