Quake 3 Arena Cheats

Unlock All Cinematics
From a dos prompt in your Quake3 directory, type:
quake3.exe +seta g_spVideos "\tier1\1\tier2\2\tier3\3\tier4\4\tier5\5\tier6\6\tier7\7\tier8\8"

Hidden Sarge Skin
Bring down console and type: /model sarge/krusade

Unlock All Levels at Skill 1
Bring down console and type: /iamacheater

Unlock All Levels at Skill 100
Bring down console and type: /iamamonkey

In order to use the following cheats in multiplayer mode, the server must have cheats enabled (ie: /devmap +map [name])

God Mode
Bring down console and type: /god

3rd Person View
Bring down console and type: /cg_thirdperson 1

All Weapons
Bring down console and type: /give all

No Clipping
Bring down console and type: /noclip

You can also use the following codes with the /give command:

allammo
armor
battle suit
bfg10k
flight
gauntlet
grappling hook
grenade launcher
haste
health
invisibility
lightning gun
machinegun
medkit
personal teleporter
plasma gun
quad damage
railgun
regeneration
rocket launcher
shotgun
mega health
speed