999 Health
To acquire 999 health, push the Tilde [~] key to bring up the console. Then type "give health 999" and push Enter.

Note: If you collect other health items, your health meter will go back to the normal 100 health.

Change Crosshair
To change the crosshair, push the Tilde [~] key and type, "Crosshairx" where x is the magnification constant; then push Enter.

Note: X is a value between 1 and 5.

Change Gravity
To change gravity, push the Tilde [~] key and type, "Sv_gravityx" where x is the gravitational constant; then push Enter.

Note: A value of 800 is "normal" gravity.

Give Command
The Give command brings forth an item or object, player or enemy. To ?give? an object, push the Tilde key [~] and type "Givex" where x is the singular form of the desired item (without spaces).

Here are a few examples:

All
Ammo
Armor
Armor Shard
Blue Key
Body Armor
Combat Armor
Commander?s Head
Health
Invulnerability
Power Cube
Power Shield
Red Key
Security Pass
Silencer
Slugs
Weapons

God Mode
Type the tilde and then type "god". Press return and you will be in God Mode.

Id Gallery (Unit 9)
To see pictures of Quake 2 staff, first defeat the final boss. Then search the grounds for a stress fracture that has formed during the struggle. Shoot the crumbling surface and enter the crawl space.

Secret Level (Unit 1, Level 3)
To reach the secret level, go to level 3 (in the first unit) and walk forward until you see a large pool. Two Light Guards and an Enforcer patrol the area. Kill them and grab the Re-breather that they protect, activating it by pressing the B button. Now wade into the pool and slither through the large crack in floor. (You will have to duck because you?re too big to enter any other way.) Once you have crawled through the crack, search for a narrow tunnel. The tunnel will lead to a tiny oasis. And once there, push the Space Bar until you discover a small "secret" room. In the room, two bodies lie next to an elevator. Step over them and push the elevator button. You?ll descend to a secret level!

Secret Room behind Waterfall (Unit 5)
In the Receiving Center (Unit 5), go to the area where you see a waterfall. With a running start, jump over the ledge and into the falls! You should land in a small corridor.

Cheat Codes
First you must press the " ~ " key and then type in the cheats below:

give all
give health
give weapons
give ammo
give armor
give body armor
god notarget
noclip
give jacket armor
give blaster
give shotgun
give super shotgun
give machinegun
give chaingun
give grenade launcher
give rocket launcher
give railgun
give bfg10k
give shells
give bullets
give cells
give grenades
give rockets
give slugs
give quad damage
give invulnerability
give silencer
give rebreather
give environment suit
give ancient head
give adrenaline
give bandolier
give ammo pack
give data cd
give power cube
give pyramid key
give data spinner
give airstrike marker
give blue key
give red key
give security pass
give commander's head
give power shield
give armor shard
give combat armor