Karma is a game mechanic measured in points. Classified by three types, good, neutral, and evil, the player character always start a new game with 0 Karma points, which is considered neutral. Wasteland inhabitants will behave differently toward the player character depending upon Karma, and it serves as a factor in unlocking certain dialogue options and game endings. Some games use both Karma and reputation as mechanics, while others use one or the other.
In Fallout 2, "general reputation" is renamed to Karma, reputation titles are kept and a new stat called "Reputation" is added, acting as a measurement of how one is perceived in specific locations or among certain groups.
In Fallout 3, although Karma is measured in points, only associated status and titles appear.
The following is based on unverified behind the scenes information and may be inaccurate.
Three of the Karma images from Fallout 2 reference a superhero, each of a different comics company including Defender references Batman of DC Comics, Shield of Hope references Captain America from Marvel Comics, and Demon Spawn references Spawn, published by Image Comics.
End of information based on unverified behind the scenes information.