 Players can code their own features into the game.While a computer science student at Purdue University, Daniel Lawrence wrote several hobbyist computer games for the university's PDP-11 RSTS/E mainframe computer, and one grew into "Telengard".In his 1976 and 1977 college summer breaks at home, he worked at BOCES in Spencerport, New York, where he wrote a dungeon crawl game called "DND" (postdating the similar but unrelated "dnd") in the BASIC programming language for the DECsystem-10's TOPS-10 operating system.