Castle of Riddles is a text adventure released by Acornsoft for the BBC Micro (in 1982) and Acorn Electron (1984) home computers. The game was written by Peter Killworth and was one of a series of text adventures written for, or ported to the BBC Micro by the same author (others including Countdown to Doom and Philosopher's Quest). As with all such games, only text is used. The player must use a simple 'verb-noun' format (e.g. 'Go North', 'Get lamp') to control the game.