Cheat mode:
Press ` to display the console, then type sp_cheats 1 to enable cheat mode:

Result - Code:

All weapons - give weapons
Toggle God mode - god
999 health and armor u- ndying
No clipping - noclip
Invisibility - notarget
Get indicated item - give (item name)
All weapons, weapon power, health - give all
Third person view enabled - cg_thirdperson 1
Third person view disabled - cg_thirdperson 0
Suicide - kill
Quits game - quit
Restart video engine - vid_restart
Set brightness; 1.0 is default - r_gamma (x.x)
Display additional information when scanning - give tricorder
Deactivate cheat mode - sv_cheats 0
Set third person view range - cg_thirdpersonrange (1-100)
Level select - map [level name]
Hidden intermission sequence - map _brig
Enable cheats for level (on server) - devmap (level name)
Set field of view; default is 80 - cg_fov (number)
Change name - name [value]
Change character model - model (model name)
Spawn indicated character - npc spawn (character name)
Kill indicated character - npc kill (character name)
Kill all NPCs in current level - npc kill all
Show current position in x y z (rotation) format - viewpos
Set current position - setviewpos [x y z (rotation)
Show current gravity setting - g_gravity
Set gravity; default is 800 - g_gravity (number)
Views ending credits - ui_closingcredits
List FMV sequences - dir video
Plays indicated FMV sequence - cinematic (filename)
Bind keys; for example: bind F12 map - bind (key command)
Set health; default is 100, 200 in easy mode - give health (number)
Set armor; default is 100, 200 in easy mode - give armor (number)
Get weapon give - weaponnum (number)