Lunatic Fringe is the eleventh level and the second secret level that can be found in the episode Lunar Apocalypse of the game Duke Nukem 3D. The player can get to this level if they find the secret exit in Dark Side.
Lunatic Fringe is quite a short level that mostly takes place in a large circular area; it appears to be some sort of Alien Space Station or possibly a former EDF space station that was overrun. However for its size, the resistance is quite fearsome as Duke Nukem will have to fight a few Mini Battlelords in the central room. There are two main areas in Lunatic Fringe; the outer circle and an inner room; the inner room being the area where the Mini Battlelords are; Duke can open up the central area by pushing all the buttons beside the large screens which is quite similar to how the centre is opened in Spin Cycle, but unlike Spin Cycle, it's less complex as there aren't as many buttons and this level doesn't finish in the centre; it finishes off in a small hallway that Duke gets into by being shrunk after hitting a button in the centre. The music is quite creepy too!
- Even for its size, this level is considered revolutionary because the player was required to run 720 degrees around it before he can get back to the starting point which really did show just how revolutionary the Build engine is. Later games have achieved it, but the game engine wasn't designed for it in mind, resulting in minor imperfections.
- The level appears to be named after the Red Rider song which was also called Lunatic Fringe.