Fudge is a flexible setting-agnostic RPG engine designed for GMs or game developers to customize for their own purposes. A version of Fudge is available under the OGL for this purpose.
The engine combines phrase-based character properties with an adjective-based rating ladder. The intended dice mechanic uses special six-sided "Fudge dice," although alternative randomization systems are available that use other types of dice, coins, or playing cards.
Fudge dice are also used by the fate engine, which was originally derived from the Fudge OGL.