There are three character types: fighter, magician, and cleric. Knight wouldn't learn who the original author of the game was until many years later. Bill Knight discovered one of these unauthorized ports and created a DOS port, adding two new dungeons – The Cavern and The Warren. The source code for the mainframe version of DND was ported to other computer systems without Lawrence's knowledge or permission. The game was sold commercially under the name of the surviving dungeon, Telengard. Lawrence eventually ported DND to home computer systems, whose limited RAM required dropping two of the dungeons and reducing the character to a single class. The games were similar, but Lawrence's game didn't contain any of Whisenhunt and Wood's source code.

Another dungeon crawl, called 'DND', was written in BASIC for the DECsystem-10 mainframe computer's TOPS-10 operating system in 1976.

A game called 'dnd' was written in the TUTOR programming language for the PLATO system by Gary Whisenhunt and Ray Wood in 19, based on Gygax and Arneson's Dungeons & Dragons roleplaying games.

Old school dungeons and dragons game