J.U.R.P.E.

J.U.R.P.E. (Java Universal Role Playing Engine) is an Open Source Java engine to support the writing of new electronic RPG games. Jurpe follows a skill based, three dice RPG ruleset.

Jurpe also comes with JurpeDemo, a full featured dungeon crawling adventure that demonstrates the capabilities of Jurpe engine.

This is a great engine for those that want to build a RPG game.

More information is available here.