Catwalk

Catwalks are a type of obstacle or trap in Doom in which the player must navigate over a very tall and narrow bridge, with long pitfall drops on either side, usually filled with a damaging liquid. Many levels in the Doom and Doom 2 feature catwalks, such as E1M1: Hangar's zigzag bridge, E1M3: Toxin Refinery's O-shaped bridge, or MAP11: Circle of Death's starting area. A catwalk can be used to make it difficult for a player to reach an item or area, as it requires the player to make very precise movements.

While catwalks can come in a variety of designs, the most dominant and manifested example of this type of obstacle appear on many parts of Doom II's MAP24. Christen Klie created a level in The Master Levels for Doom II titled "The Catwalk" where a catwalk must be quickly ran across before it crumbles to the floor to reach the exit.