Walls (Rules) (GM Core)

Well-built structures have exterior walls of steel, concrete, brick, or stonemasonry. Smaller, lower-quality, or temporary structures might have wooden or plastic walls. Interior walls tend to be less sturdy; they could be made of wooden planks, or even simply of thick, opaque paper held in a wooden frame. An underground structure might have thick walls carved out of solid rock to prevent the weight of the ground above from collapsing the structure. Rules for climbing and breaking walls are in the sidebar under Urban environment.