Both Crowther and his wife Patty are dedicated spelunkers—she is noted as the discoverer of the subterranean connection between the Mammoth Cave and Flint Ridge cave systems.
During the early 1970s Crowther worked at defense contractor and Internet pioneer Bolt, Beranek and Newman (BBN). There, in his spare time, Crowther wrote a simple text-based adventure game. In this the player would move around an imaginary cave system by entering simple commands and reading text describing the result. Crowther used his extensive knowledge of cave exploration as a basis for this, and there are many similarities between the locations in the game and those in Mammoth Cave, particularly its Bedquilt section. In 1975 Crowther released the game on the early ARPANET system, of which BBN was a prime contractor.
The following year he was contacted by Stanford researcher Don Woods, seeking his permission to enhance the game. Crowther agreed, and Woods produced several enhanced versions and ported it to the PDP-10 minicomputer. Over the following decade the game gained in popularity, being ported to many operating systems, including personal-computer platform CP/M.
A number of the basic features invented by Will Crowther were carried forward by the designers of later adventure games—in particular the Zork adventures show this ancestry particularly clearly.