A coding that I know some MUDs use, and the command I made for IRC was a command that is used to change things about certain mobs on the fly, like weight, str, etc.

You can also screw with people with it by executing procs, like @.bob->i_die() would cause the target, bob, to be killed instantly by running the i_die() proc.

Best I can tell you is look it up online, and more than likely, you'll run into many examples being MUDs.