To unlock Zombie mode, pause the game and press up, down, up, down, left, right, left, right.
Intel pieces unlockables:
Collect the following amounts of intel pieces to unlock the corresponding cheat options:
INTEL PIECES – CHEAT OPTION
Collect 15 intel pieces – A Bad Year: Enemies explode into tires when shot.
Collect 10 intel pieces – Cluster Bombs: When a frag grenade explodes, four more will explode in a cross-shaped pattern.
Collect 2 intel pieces – CoD Noir: Graphics turn black and white)
Collect 30 intel pieces – Infinite Ammo: Reloads are no longer necessary. This has no effect with single-shot weapons such as RPGs, C4, or claymores.
Collect 4 intel pieces – Photo-Negative: Inverts the colors.
Collect 8 intel pieces – Ragtime Warfare: Silent movie mode.
Collect 20 intel pieces – Slow-Mo Ability: Slows game to half speed when you melee.
Collect 6 intel pieces – Super Contrast: Increases the contrast.
Intel piece locations:
The corresponding amount of intel pieces are located in the following levels:
LEVEL – INTEL PIECES
Level 2 – 2 intel pieces
Level 4 – 2 intel pieces
Level 5 – 3 intel pieces
Level 6 – 2 intel pieces
Level 7 – 2 intel pieces
Level 9 – 3 intel pieces
Level 10 – 2 intel pieces
Level 12 – 2 intel pieces
Level 13 – 3 intel pieces
Level 14 – 2 intel pieces
Level 16 – 2 intel pieces
Level 17 – 1 intel pieces
Level 18 – 2 intel pieces
Level 19 – 2 intel pieces
To unlock Arcade mode, beat the game.
To unlock Prestige mode, reach level 55. It is a multiplayer-only mode that starts you again at level 1.
To unlock the Epilogue mission, complete the game and watch the entire credits.
Mile High Club mission:
To unlock the Mile High Club mission, complete story mode under any difficulty setting.
Unlock the following Golden Guns by completing the corresponding weapons challenges. Note: This does not boost the guns performance; only the appearance is changed:
GOLDEN WEAPON – HOW TO UNLOCK
Golden Ak-47 – Complete all assault rifle challenges.
Golden Desert Eagle – Reach level 55.
Golden Dragonuv – Complete all sniper challenges.
Golden M1014 – Complete all shotgun challenges.
Golden M60 – Complete all LMG challenges.
Golden Mini-Uzi – Complete all SMG challenges.
Reach the following ranks in Multiplayer mode to unlock the corresponding bonuses:
Level 1 – All starting equipment
Level 2 – Demolitions class weapon class
Level 3 – Sniper class weapon class
Level 4 – Create a class
Level 5 – Gun challenges
Level 6 – New playlists
Level 7 – M21 Sniper rifle
Level 8 – Last stand perk class 3
Level 9 – Boot camp challenges 1
Level 10 – M4 carbine assault rifle
Level 11 – UAV jammer perk class 2
Level 12 – Clan tag
Level 13 – Mini uzi submachine gun
Level 14 – Bomb squad perk class 1
Level 15 – Boot camp challenges 2
Level 16 – M1911 pistol
Level 17 – Martyrdom perk class 2
Level 18 – Boot camp challenges 3
Level 19 – M60E4 light machine gun
Level 20 – Sleight of hand perk class 2
Level 21 – Operations challenges
Master Gunnery Sergeant
Level 22 – Dragunov sniper rifle
Level 23 – Claymore perk class 1
Level 24 – Operations challenges 2
Level 25 – G3 assault rifle
Level 26 – Iron lungs perk class 3
Level 27 – Operations challenges 3
Level 28 – AK-74U submachine gun
Level 29 – Double tab perk class 2
Level 30 – Killer challenges
Level 31 – M1014 shotgun
Level 32 – Bandolier perk class 1
Level 33 – Killer challenges 2
Level 34 – R700 sniper rifle
Level 35 – Eavesdrop perk class 3
Level 36 – Killer challenges 3
Level 37 – G36C assault rifle
Level 38 – Overkill perk class 2
Level 39 – Killer challenges 4
Level 40 – P90 submachine gun
Level 41 – Frag x3 perk class 1
Level 42 – Humiliation challenges
Level 43 – Desert eagle pistol
Level 44 – Dead silence perk class 3
Level 45 – Humiliation challenges 2
Level 46 – M14 assault rifle
Level 47 – Humiliation challenges 3
Level 48 – Humiliation challenges 4
Level 49 – Barret sniper rifle
Level 50 – Humiliation challenges 5
Level 51 – Elite challenges
Level 52 – MP44 assault rifle
Level 53 – Elite challenges 2
Level 54 – Elite challenges 3
Level 55 – Commander prestige mode and golden desert eagle
A metal “ping” sound will confirm a headshot kill.
Better aiming accuracy:
Use the red dot scope over the ACOG scope. The red dot will give you a better aimpoint on most weapons. The ACOG scope will actually add more range, but take away accuracy.
Level up quicker:
Use the same gun until all the marksman and elite challenges are completed. This will quickly level you up to new guns, but do not use them. Keep using the same one you started with until the challenges are completed.
Multi-player prestige medals:
Reach the following ranks to unlock the corresponding prestige medals:
RANK – MEDAL
Level 1 – Gold shield with silver eagle.
Level 2 – Blue titanic diamond with star spikes.
Level 3 – Emerald in the middle with four lines with circles on the ends.
Level 4 – Black circle in the middle with white, gold, maroon, and tan edges.
Level 5 – Gold badge with one eye in the middle.
Level 6 – Gold eagle in the middle with six lines.
Level 7 – Thin cross with wings on the outside and a square gold lined sheet in the middle.
Level 8 – Red diamond in middle with a triangle shield on the outside with gold and white trim.
Level 9 – Maroon and black Star Of David.
Level 10 – Gold iron cross.
All Ghillied Up: Easy Intel Pieces:
Go to the location of the first Intel Piece, located at the top of the ladder in the first church. Get the Intel Piece and fall back down. You will die and start out getting the Intel Piece again. The Intel Piece keeps adding to the total number that you have. Repeat this process until you have 30 Intel Pieces.
Crash: Good sniping position:
Note: You can do this only in multi-player matches. Go to a multi-player match at the “Crash” map. Make sure it is an Old School match. Go to the location of the helicopter crash. There is a very tall building that should be easy to identify. Climb all the way to the top of the roof. Get up onto the blue box-like “vents”. Look over at the little open door where you came out of (if you went through the building, and not up the ladder). Sprint for a brief moment, then jump onto the top of that little roof object. If done properly, you should land on the roof. Jump over onto the fenced part. This is easy because the boundaries are set there, so you cannot fall off. Carefully walk up on the fence where you see a somewhat shorter building. Sprint, then jump. If done properly, you should have landed on a roof with a satellite dish. This roof has a great view over the crash and the people will have no idea where you are. This is a great spot for sniping or heavy gunning. It is probably not as useful when using SMGs.
Televisions never go off:
When throwing regular and/or flash grenades at televisions that are on, they will at times still keep working even though they have been blown up.
Crossfire: Sniping location:
Play the old school free 4 all section. Note the building at the very end of the map on the opposite side of the bus. Get to the very top of the building that is around the corner. Do to so, first get to the second story where the chair is found. Get on the top of the chair facing the wall and jump. You may have to run and jump, but eventually you will catch an edge. You can then work your way up to the position. Once there, go to your right. Then, jump up onto the object just past the building that you are currently on. Walk around the building, trying to stay as close to it as possible. Then, look down. Make sure you are directly above the barbed wire. Follow that until you get to the building, then jump onto it. Then, just walk across to the other building. Note: You will be floating in air. When you get there, go to the extreme left of the building. Jump and you will notice a glitch — you are on an invisible object. Once you get there, jump again to get on top of the building. Then, go backwards but do not go off the building. Run and jump just when you get to the front edge. You will now be floating in the air. When you are almost on the fence below, you will fall. When you fall, walk directly along with the fence or else you will fall. You can just crouch and shoot people.
Have three guns:
To do this trick you must have the Overkill (level 38), and the Last Stand (level 8) perks enabled. The Overkill perk should give you two primary weapons of your choice. Play a game and use this class. When you are put into Last Stand, you will get an M9. You cannot choose the pistol you want. Note: You can only use the M9 when you are in Last Stand.
When you choose an attachment for a weapon it takes up the first perk. To stop this, select your perks then choose your weapons and attachment. You will then have three perks and a weapon attachment.
Turning televisions off:
To turn a television on or off, walk up to it and hold SQUARE.