Hidden Tradition is a multiplayer game server using the Neverwinter Nights engine, based on a fantasy version of Earth in the 12th century. The server runs a recreation of areas of Europe and Palestine during the Crusades of the Middle Ages. It is quite detailed in many ways, so much so that the world maps used for the game are actual maps from that period of history. However, it is an alternate-Earth version of the Crusades, one with elves, dwarfs, etc. in traditional D&D style. In fact, the world of Hidden Tradition is pretty much the way that people who lived during that time actually saw it. There may not have really been elves back then, but people believed there were.