1. If you want to unlock dead ops arcade mode enter the code 3ARC UNLOCK in the little computer screen
2. In 'Five' in zombies, to get up on table where zombies can't reach you go down to the large screen and face away from it straight up the room. Go to the door on the very right and break the bottom half of the glass and rebuild the barrier. Jump up the two planks of wood and then to the top of the doorframe and jump down onto the table.

1. When you are with another person you can do this cheat. Have one person go to the wall with the M1A1 Carbine and lay down on the ground by the crates. Crawl foward a few inches. Next the second player runs and jumps on top of the person laying down. Make sure the arrow that says where the team mate is at is pointing straight up. Next the person on top walks towards the crate and wall while the other person stands up. Now neither player must knife, throw grenades, or touch the left joy stick. The zombies can't touch you. To get out of this cheat just walk in any direction