Doom 3: Resurrection of Evil - Skip Checkpoints

God Mode:
Hold L and press X, Y, B, A during game play. A sound will confirm correct code entry. Note: The code cannot be enabled until you take the elevator after being attacked at the start of the game. When a new area is loaded, the code must be re-entered to regain its effect.

Chainsaw in Doom 2 and Ultimate Doom:
While playing a game, hold L and press B2, A2. If you entered the code correctly, you will hear a sound.

Full map in Doom 2 and Ultimate Doom
While playing a game, hold L and press Y4. If you entered the code correctly, you will hear a sound.

All weapons, health, keys, and armor in Doom 2 and Ultimate Doom
While playing a game, hold L and press B4. If you entered the code correctly, you will hear a sound.

Level skip in Doom 2 and Ultimate Doom
While playing a game, hold L and press A2, B2. If you entered the code correctly, you will hear a sound.

Light amplification goggles in Doom 2 and Ultimate Doom
While playing a game, hold L and press Y3, X. If you entered the code correctly, you will hear a sound.

Radiation suit in Doom 2 and Ultimate Doom
While playing a game, hold L and press X, Y3. If you entered the code correctly, you will hear a sound.

Secret web site and code:
On the Phobos Labs Sector 2 level, located in the Commons area, play all five levels of the Martian Buddy Blaster mini-game. Upon winning, you will receive a message in your personal PDA giving you this link:
https://www.martianbuddy.com/blaster.html. This is one of two ways to get the code 634 for lockers 116 and 117 in the Delta Labs. The second method is to get the Patrick Hook PDA.

Storage locker combinations
Locker - Code - Contents
009 - 492 - Security Armor, Machinegun Ammo, Chain Gun Ammo
029 - 516 - Security Armor, Machinegun Ammo
034 - 134 - Machinegun Ammo, Chain Gun Ammo
035 - 134 - Pistol Rounds, Shotgun Shells, Armor Shards
042 - 714 - Shotgun Shells, Chain Gun Ammo
105 - 769 - Pistol Rounds, Shotgun Shells, Hand Grenades
116 - 634 - Shotgun Shells, Plasma Cells
117 - 634 - Shotgun Shells, Chain Gun Ammo
407 - 937 - Pistol Rounds, Shotgun Shells, Small Med-kit
408 - 937 - Shotgun Shells

Temporary invincibility in Doom 2 and Ultimate Doom
While playing a game, hold L and press X4. If you entered the code correctly, you will hear a sound.

Toggle Berserk mode in Doom 2 and Ultimate Doom
While playing a game, hold L and press X3, Y. If you entered the code correctly, you will hear a sound.

Toggle God and Degreelessness mode in Doom 2 and Ultimate Doom
While playing a game, hold L and press A4. If you entered the code correctly, you will hear a sound.

Toggle invisibility in Doom 2 and Ultimate Doom
While playing a game, hold L and press X2, Y2. If you entered the code correctly, you will hear a sound.