No DOOM level is complete without it's assortment of monsters, weapons, items and the occassional barrel. In level-editing terminology these are called Things. Basically, everything in a level that is not a wall, floor or ceiling is a Thing.
Hellmaker offers you a complete selection of things; you use Thing Mode to place, move and change things. There are a couple of important rules to remember:
(1) Every level MUST have one Player 1 Start thing. Without it, DOOM will just crash. In addition, levels for deathmatch must have four to ten Deathmatch Starts, and co-operative levels must include starts for the other players. You should probably put all of the player starts and at least four deathmatch starts in every level you make.
(2) Some Things are only available when you're playing DOOM 2. Hellmaker highlights these things in red in the things menu. You must not use these things in Ultimate DOOM wads.
Thing Attributes:
Each thing has a number of attributes that can be set:
1+2, 3 and 4+5: The thing will only appear at the specified difficulty levels.
Multi: The thing only appears in multplayer games (i.e. Deathmatch).
Deaf: Only for monsters. When a monster is deaf it will not "wake up" if it hears a sound made by the player. It will only start moving when it sees the player, or is attacked.
Facing: This is the direction the thing is initially facing. Only applies to monsters and player starts. For teleport destination things, it is the direction the player/monsters face after teleporting.
