Call of Duty: World at War/Mystery Box

The Mystery Box is a utility in the immensely popular Zombie Co-op mode in Call of Duty: World at War and Call of Duty: Black Ops.

Details
The Mystery Box's main function is a random weapon generator that costs only 950 points for a player to use. In Black Ops and World at War, there is a large weapon variety which can be obtained, but different items offered up by the box can lead to significant changes in what a player can do with it to last into the later rounds.

World at War Strategy
The Mystery Box in the introductory Zombies map, Nacht Der Untoten (Literally Night of the Living Dead in German), has a significant advantage all other Zombies maps don't have; it does not roam around the map after being used a certain number of times, meaning that it could be a wise investment to leave a crawler in between rounds and spend all one's money on the device. This Strategy also applies to the remastered Black Ops version as well.