| Code | Effect |
| Crosshair 1 | Gives you crosshairs |
| Fly | Flying mode (D=up C=down) |
| Fov X | Increases peripheral vision (where x is your field of vision) |
| Give #x | gives weapon #x - 3=shotgun, 4=nailgun, etc.. |
| Give C #x | Gives x # cells |
| Give H #x | Gives x # health |
| Give N #x | Gives x # of nails |
| Give S #x | Gives you x # of shells |
| Give R #x | Gives you x # of rockets |
| God | God Mode |
| Impulse1 | Shotgun |
| Impulse2 | Super Shotgun |
| Impulse3 | Nailgun |
| Impulse4 | Chain Nailgun |
| Impulse5 | Grenade Launcher |
| Impulse6 | Rocket Launcher |
| Impulse9 | All Weapons |
| Impulse252 | Pentagram of Protection (30 seconds) |
| Impulse253 | Ring of Shadows (30 seconds) |
| Impulse254 | Bio-suit (30 seconds) |
| Impulse255 | Quad Damage mode |
| Kill | Commit suicide - restart level |
| map e#m# | Level Warp |
| Map End | Takes you to last level |
| Noclip | Walk through walls |
| Notarget | Invisible to enemies |
| R_Fullbright 1 | Everything is bright |
| sv_gravity ### | sets gravity to ### |
| Version | Gives you version information |
or...
Step into the water but don't fall through. Swim all the way against the wall on the same side you enter the water (where the shield is in deathmatch). Now fall through and you will land on the rafter. Walk on the rafter right into the Nightmare entrance.
If you have a hard time getting anywhere on the rafters, use the NoClip code and walk through walls until you find it.
To be invisible to your deathmatch buddy but not the monsters,
type: R_Drawviewmodel 0.