Start the game with the +set monkeytoy 0 +set sv_cheats 1 command line parameter. Press ~ during game play to display the console window. Enter one of the following codes at the console window to activate the corresponding cheat function. Note: If the game responds "sv_cheats are read only", then type setrandom sv_cheats 1 in the console before activating the codes.

Effect - Code

No clipping mode - noclip
Invincibility - god
Spawn indicated item - give
Full health - give health
Ignored by enemy - notarget