Drawing on the eight or so hours he had spent playing Rogue at UCB, Fenlason laid groundwork in San Francisco. His intention, more or less, was to recreate Rogue as he remembered it: the dungeon layouts, the monsters, and the items. Fenlason dubbed his clone Hack for two reasons: "One definition was 'a quick [computer] hack because I don't have access to Rogue'. The other was 'hack-n-slash', a reference to one of the styles of playing Dungeons and Dragons."
Thus the roguelike, a game clearly inspired by Rogue rather than coincidentally exhibiting similar game systems and features, was born.
Fenlason composed a wish list of features he felt Rogue lacked, as well as those which Rogue could have implemented better. Level design, for instance, had been too simplistic; it would be more fun if players could explore dungeons that spanned more than a single screen. Monsters posed another shortcoming. There were only twenty-six, one per capital letter—far fewer than the text symbols available. More egregious was that they all attacked in the same way, making a beeline for the player instead of, say, maneuvering around for a sneak attack or standing in place—perhaps blocking a doorway—and forcing the "@" avatar to venture closer.The entire sneak peek is available here, and is well worth your time to read.