People under the stairs: While on the map 'The Pit', if you consider the Sword room to be north, you can hide under the ramp just outside of the shotgun room in the south east corner of the map. Although this is only beneficial in certain games such as Infection, to get under the stairs continually walk towards the space under the ramp while repeatedly pressing and releasing the crouch button. Master this technique in forge before attempting in a real match.