Various cheats
     Press  [Esc]  during  game  play to display the pause menu. Then,
press  ~ to display the console command prompt, which will be a bright
line  with  an input prompt below the menu. Enter one of the following
codes  to  activate  the  corresponding cheat function for the current
level.
     Note  You  will not be able to see what you are typing. Also, you
must re-enter the cheats for each level as they get reset.

Alternately, press [Tab] during game play.
     You  will  see a white line at the bottom of the screen where you
can type in the codes, and be able to see what you are typing.

Various cheats:              Result:
allweapons                   All weapons
loaded                       All weapons and ammunition
walk                         Disable flight and no clipping
ghost                        No clipping
amphibious                   Stay underwater without damage
teleport                     Teleport to area currently looked at
changesize <number>          Scale player size
changesize                   Restore default player size
setspeed <number>            Set player speed
setjumpz <number>            Set maximum jump height
setgravity <number>          Set gravity
slomo n                      Set slow motion factor
viewself                     Set camera to behind view
freecamera <true or false>   Camera and pawn not rotated together when True
invisible <true or false>    Toggle invisibility
avatar <class name>          Possess a pawn of indicated class
summon <class name>          Summon requested class
killpawns                    Kill all pawns and enemies
God                          God mode
allammo                      999 ammo for all weapons
fly                          Toggle flight