The Mayfair Exponential Game System or MEGS is a rules system developed for role-playing games. It is noteworthy for its use of an exponential system for measuring nearly everything in the game. This system makes it possible to have both cosmically-powered characters and ordinary human characters meaningfully interact within the same universe. For example, in DC Heroes, the first game to use MEGS, Superman's strength is several orders of magnitude more than Batman's. With the MEGS system, however, this large difference in strength is scaled down. So, while Superman would still have a clear advantage in a brawl, Batman is at least able to hold out for a while, mirroring how superhero combat often operates in comic books.
Source: Wikipedia Mayfair Exponential Game System available under the CC-BY-SA License.