By the time Toy and Wichman started at UC Santa Cruz, BSD UNIX had entered widespread usage across UC campuses and was branching out to other schools. Each new version of BSD, released on cassette tape, included handy programs written by Joy and other hackers. One program was curses, written by Ken Arnold. Arnold had written curses according to the UNIX creed: a simple tool fashioned for a specific purpose. Wielding curses like a paintbrush, users could place text such as letters, numbers, and symbols at any location on the screen.

The moment he used curses, Toy saw its potential. In 1980, he went to Wichman and suggested they use curses to create a graphical adventure game with a twist. Unlike Colossal Cave Adventure and its derivatives, their game would construct brand new environments and challenges every time. An avid Dungeons & Dragons player, he invented a fantasy-themed setting and premise. Players would assume the identity of an adventurer who entered the Dungeons of Doom, a series of levels filled with monsters and treasure. 

Wichman loved the idea and dubbed the game Rogue. "I think the name just came to me. Names needed to be short because you invoked a program by typing its name in a command line. I liked the idea of a rogue. We were coming from a Dungeons & Dragons background, but we were creating a single-player game. You weren't going down into the dungeon with a party. The idea was that this is a person going off on his or her own. It captured the theme very succinctly."

Apropos of UNIX, Toy chose to write Rogue in the C language. C produced fast code, while BASIC was slower and meant for smaller programs. Wichman, still a few steps behind Toy in programming prowess, learned C by watching Toy program their game. "The early alpha versions of Rogue were probably all my code, but Glenn [Wichman] made lots of contributions in terms of design," Toy recalled. "I think it's quite fair to say that the game was a pretty straight collaboration between Glenn [Wichman], Ken [Arnold], and me by the time it was done. I feel pretty good about that."

Toy and Wichman realized they wouldn't be able to stay at school during all hours to write their game. Fortunately, they didn't need to. As employees of the computer science division, they had special lab privileges. Setting up an ADM-3a terminal in their apartment, they could dial into the VAX 11/780 shunted off in a basement somewhere at UC Santa Cruz. The connection was established through their 300-baud modem -- a device that would take several minutes to transmit the text on an average-length Wikipedia page today -- enabling them to write the vast majority of Rogue from the comfort of their apartment.