The popularity of the game rests more on the immense amount of variants available for it. The most popular one is Zangband, based on the writings of Roger Zelazny. Other variants modeled off the works of H.P. Lovecraft, Anne McCaffrey, David Eddings, and also modify the rules, like adding multiplay capability, or switching the class system with a skill system, or just centering the game around a new class, creature, or item. In fact, most people consider this "vanilla angband", to be more of an example, perhaps to start someone out on the game, or to provide a baseline to compare other versions to. And, of course, to make more variants from!