Call of Duty: Black Ops Easter eggs guide

Saving the world is serious business, but that doesn't mean you can't have a little silly fun along the way. Treyarch, the developers behind Call of Duty: Black Ops, have made a game about war, torture, interrogation, assassination, political intrigue and vast government conspiracies.

If you look closely and carefully enough, however, they've also made a game with cuddly children's toys, hilarious internet memes, '80s arcade machines, old-school text adventures and subtle nods to the franchise's past. What, where, when and how, you ask? Read on for our 15 favorite Call of Duty: Black Ops Easter eggs... so far.

Contributor: Joe McNeilly

Escape your chair in the main menu

What a cool concept. You don't just play as secret soldier Alex Mason during the game… you play as him in the menu screens as well. Still strapped to the interrogation chair. Still questioned by that mysterious shadow. Still surrounded by flickering monitors and dirty torture equipment. You can look around all you want, even down at your imprisoned arms and legs, but you can never escape.

Or can you? You can! Simply pull the left and right triggers on your controller, in quick and alternate succession: LEFT, RIGHT, LEFT, RIGHT, LEFT, RIGHT, LEFT, RIGHT, LEFT, RIGHT. Do it fast enough and Mason will suddenly break free of his restraints and stand up, free to explore the room.

BONUS: Finding this Easter egg will earn you the Achievement / Trophy "Just ask me nicely"

Access a secret computer terminal

Once free from the interrogation chair, the first thing (really, the only thing) you'll want to do in this menu room is walk over to the small computer terminal tucked away in the back corner. The game will instruct you to hit a button, and voila – a really old, really clunky '60s-era operating system!

Type out "HELP" for a basic idea of what commands are possible in this retro terminal. We'll walk you through the documents and programs we've found so far, but if you experiment enough, you're bound to discover something new. Also, if you own a USB keyboard, we recommend plugging it in now.

Unlock the Dead Ops Arcade mode

You've played Nazi Zombies and, after beating the campaign, you've played Pentagon "Five" Zombies with JFK, Castro, Nixon and McNamara. But what about that third missing option, currently blacked out in the Zombie menu? What unlocks that?

Simple. At the computer command prompt, enter "DOA" to launch Dead Ops Arcade, an old-school, top-down, dual-stick shooter similar to Robotron, Smash TV or Geometry Wars… only with armies of zombies, remote control helicopters and an evil space gorilla. It's fun, it's surprisingly lengthy and best of all, it supports co-op. After you've entered the "DOA" code and played that first time, Dead Ops Arcade will always be available from the main menu.

BONUS: Finding this Easter egg will earn you the Achievement / Trophy "Insert Coin"

BONUS x2: Using the Speed Boost power-up in Dead Ops Arcade to kill 20 or more enemies at once will earn you the Achievement / Trophy "Easy Rhino"

Play Zork

Yes, buried within one of this year's most high-budget, cutting-edge, action-packed explosion-thons is a 1980 text adventure in which you solve puzzles, navigate mazes and defeat trolls by typing at them. Zork I: The Great Underground Empire is a legendary milestone in the history of gaming and, should you grow bored of all the guns (or all the graphics) in Black Ops, it is fully playable when you type "ZORK" into the computer terminal's command prompt.

BONUS: Finding this Easter egg will earn you the Achievement / Trophy "Eaten by a Grue"

Letters from your family

We're not done with the computer yet. In addition to playing the Zork and Dead Ops Arcade programs, you can access a whole list of documents hidden in the machine. Enter "DIR" to see a list of what's available, then type "CAT" followed by a space and the filename you want. Most interesting to us were the tragic series of letters from Alex Mason's father and sister, which add dimension to his personality and background.

Hidden art and music

There are also .pic and .snd files that can be accessed through the "DIR" and "CAT" commands. The former display concept art of missions and characters, while the latter play soundtrack music from the game.

No Russian? Well, maybe a little

The most famous line of dialogue in any Call of Duty – ever – is spoken by Modern Warfare 2's terrorist villain, Vladimir Makarov, at the start of the game's fourth mission. As an elevator door slowly opens, and an airport full of soon-to-be-slaughtered travelers is horrifyingly revealed, he reminds the player, "Remember, no Russian."

Cut to the beginning of Black Ops' fourth mission, in which another undercover protagonist is about to infiltrate a Soviet launch facility. As he straps on his boots and pulls on his mask, the character across from him turns and says, "I hope your time in Vorkuta helped your Russian, Mason."

Coincidence? Or intentional callback? We're going with the latter.

Mysterious objectives

SPOILER ALERT! By the final two missions of Black Ops' campaign, protagonist Alex Mason has gone a bit coo-coo. He's paranoid, he's violent, he's hallucinating… and in a clever breakthrough of the fourth wall, the game transfers some of that madness to the you, the player. Pause during either the Revelations or Redemption missions and you won't see a real objective – just more of the numbers that have driven Mason out of his mind.

Next page: Double rainbows, teddy bears, Apocalypse Now and more!