Beyond the Tesseract

Beyond the Tesseract is a text-based adventure game developed in 1983 by Canadian author David Lo for the TRS-80. The game was notable for its unique take on the genre and approach to mathematical entities and abstract concepts. In one section the player must navigate a text adventure game, inside the text adventure game. In another the player, while asleep, derives a proof using physical representations of various symbolic logic components.

The game is intentionally vague using a VERB NOUN gameplay mechanic with a vocabulary of just 200.

In 1988 the game was rewritted from BASIC to C as V2.0, for MS-DOS and Atari ST; included was a patch file for V2.0p making it portable to Unix environments. It was published on Usenet that year, where it received a small patch submitted to fix issues in the Unix port, which became version V2.1p. In 2003, it was ported with minor modifications to the Z-machine interactive fiction standard virtual machine by Andrew Plotkin.