St. Andre is the original designer of the 'pen-and-paper' role-playing game
Tunnels & Trolls which was first released by Flying Buffalo, Inc. in 1975. In addition to writing the game rules, Ken was one of the creators of solitaire adventures which allowed players to experience the game without a game master or judge.
St. Andre has written many modules and stand alone adventures for Tunnels and Trolls. Some of his titles include:
- The Deathtrap Equalizer Dungeon
- Naked Doom
- Arena of Khazan
- Goblin Lake
- The Lair of the Silver Serpent
- The Toughest Dungeon in the World
- Agent of Death
- Strange Destinies
- Hot Pursuit
He also worked as a designer on the role-playing games
Stormbringer and
Monsters! Monsters!, and the computer game
Wasteland. In 2008 he modified the 7th edition Tunnels and Trolls to bring the game world into modern times and turned it into a superhero rpg called Power Trip.
In 1986 Ken was also the first editor for a fan club newsletter based around the
Adventure Construction Set computer game, one of the rare cases of a professional designer leading gamer activities for another designer's game.