During the game press the tilde (~) key to open the console window, where you can type in the following codes:
God Mode -- GOD
Fly Mode -- FLY
Fly Mode Off -- WALK
No Clipping -- GHOST
Add More Ammo -- ALLAMMO
Get Rid of Artifacts -- FLUSH
Open Map -- OPEN followed by the map name (two separate words)
Summon Command -- Summon followed by the requested item, player or enemy (e.g.. SummonRifle)
Third Person Perspective -- BEHIND VIEW 1
Back to First Person Perspective -- BEHIND VIEW 0
