im not sure but are there any kind of old school traps (like in HL1) that can be used in HL2DM? I remember in a map in old deathmatch there was a button you pressed and air raid sirens would go off and everyone would die shortly after if you didnt seek shelter. i think the map was called crossfire. or in tfc i remember when someone pressed a button nerve gas would permeate the air and everyone would slowly die. id like to perhaps create that nerve gas trap in my HL2DM map that can be pressed once every few minutes and kill everyone in a certain room, but ive no clue where to start. anyone know how i might be able to do this?