• Even though the game environment is dark, you can still change your display’s settings to lighten it a bit. That may help identify what’s lurking in the shadows. And don’t forget that you carry a flashlight with you at all times — use it after you’ve cleared a room of monsters and want to look for ammo and other items.
• The game supports surround sound, so if your Mac has such a speaker set-up, pay attention to the noises coming out of it. They’ll help you figure out what’s coming your way, and from which direction.
• Switch to the shotgun when you enter a room, just in case something is right behind the door. It’s the most lethal weapon in the game from close range, aside from the chainsaw, which is deadly but requires a few seconds to kill its target, time a monster can take to inflict damage.
• Aim for the head. One clean headshot will put down most enemies.
• Shelves can provide good cover for fireballs and similar attacks, while still allowing you to fire bullets.
• Don’t shoot out windows unless you have to. Some of them lead to the outside, which means you’ll let all the oxygen out of the room. And that’s not a good thing.
• Backtrack whenever necessary to pick up medkits, ammo and other items that you didn’t need before but could use now.
• Before all Hell breaks loose, you can kill some of the NPCs in the game, such as the marine waiting by the airlock before you head outside to the old communications array. Sometimes their PDAs will impart useful information.
• Whenever possible, stick to known territory while fighting monsters. If you move into a new spot during the battle, you could come within range of new enemies who will also attack.
• If you’re in an open area and multiple monsters attack, try to retreat into a hallway or other confined space, if possible. This will force the monsters to come at you one at a time and you can pick them off easier.
• When you find the Super Turbo Turkey Puncher 3 game in the cafeteria at the beginning, play it until you reach a score of 25,000 and then check your PDA for a new e-mail.
• Be sure to also watch the ticker running along the bottom of the newscast on the TV in the cafeteria.
• Visit Martian Buddy to obtain a special code that gives you better weapons at some of the storage lockers.
• Make sure the video detail setting is at High or Ultra and look over the shoulder of the guy at the reception desk. He’s typing an amusing e-mail.
• Beat the game to unlock Nightmare difficulty, in which your health drops every few seconds but you have access to the Soulcube from the start.
• Don’t waste your most powerful weapons’ ammo on monsters that you can dispatch with the pistol or other lesser weapons.
• Quick-save often, especially when you’re about to enter a new area, so that you can start over just before things went south, instead of at the beginning of the level.
• If one demon injures another, the hurt one will ignore you and attack its brethren. Only high level monsters will do this, however, and they will only attack lesser demons. Use this information to your advantage whenever possible. Moving into a spot that causes underlings to hit a boss monster, for example, can buy you time to fire off a few rounds while the big guy takes out his anger on the little ones.

Stumped? Then you may need some help, thanks to the cheat codes that are commonly placed in most videogames. They allow you to, well, cheat and change the rules. This sometimes includes activating bonuses, unlocking secrets and new levels of gameplay.

To enable the cheats in Doom 3, press the Tilde (~), Control and Option keys simultaneously to bring up the console and type in the code you want to activate. Some codes, such as god mode, may need to be reactivated each time you enter a new level, start a new game, or load a saved one. The up arrow on your keyboard enables you to cycle through codes previously entered during the current gaming session, which saves plenty of typing time. Press the Tilde key to close the console.

When you jump ahead to another level in the game with one of the map codes, you start with the weapons you would have had if you accessed it through normal gameplay, along with a small amount of ammo.

You can also spawn most of the monsters found in the game. Just make sure you turn on god mode first.

• spawn monster_zombie_maint_nojaw
• spawn monster_demon_archvile
• spawn monster_zombie_tshirt_bald
• spawn monster_zombie_sawyer
• spawn monster_demon_cherub
• spawn monster_zombie_maint2
• spawn monster_zombie_fat2
• spawn monster_zombie_fat_wrench
• spawn monster_demon_hellknight
• spawn monster_demon_imp
• spawn monster_zombie_jumpsuit
• spawn monster_demon_maggot
• spawn monster_demon_mancubus
• spawn monster_zombie_maint_flashlight
• spawn monster_zombie_maint_wrench
• spawn monster_demon_pinky
• spawn monster_demon_revenant
• spawn monster_zombie_maint_skinny
• spawn monster_zombie_suit_skinny
• spawn monster_zombie_skinny
• spawn monster_zombie_suit_bloodymouth
• spawn monster_zombie_suit_neckstump
• spawn monster_demon_tick
• spawn monster_demon_trite
• spawn monster_demon_wraith
• spawn monster_zombie_tshirt_blown
• spawn monster_boss_cyberdemon
• spawn monster_boss_guardian
• spawn monster_boss_guardian_seeker
• spawn monster_boss_sabaoth
• spawn monster_boss_vagary
• spawn monster_zombie_commando_cgun
• spawn monster_boss_cyberdemon
• spawn monster_zombie_fat
• spawn monster_flying_cacodemon
• spawn monster_demon_hellknight
• spawn monster_demon_cherub
• spawn monster_zombie_bernie
• spawn monster_zombie_boney
• spawn monster_demon_imp_crawler
• spawn monster_boss_guardian_spawner
• spawn monster_zombie_commando
• spawn monster_demon_tick
• spawn monster_demon_trite

Do Ya Mind, Buddy? Stop by the restroom and check yourself out in the mirror. Just watch out for whatever might be lurking in the stalls.

Surprise! You never know where a beast will pop up.

Change the Channel! Quick! Just your luck: You find the scientist, but it looks like someone didn’t pay the TV bill.

A Marine and His Robot. These dog-like robots can lead the way if you’re in a jam, but stay on the offensive or the zombies will destroy them.

The Security Inspections Were a Bit Lacking. You’ll find plenty of videos you can download to your PDA and watch for their amusing irony.