Once he started publicizing his rules, others were quick to point out the existence of Dungeons & Dragons, and thus Rules of the Game of Dungeon quickly fell into obscurity. He therefore created fifty copies for distribution at the World Science Fiction Convention at the end of August 1974, and circulated his rules through Minneapa. VanGrasstek recognized that there was little standardization among the rules of these dungeons, but he nonetheless hoped to write up an account of the game that would let people outside Minneapolis share in the fun. Craig VanGrasstek played in the first incarnation of "Castle Keep," and later ran a dungeon as the Foreword to his rules observes, there were nine total dungeons based on "Castle Keep" in Minneapolis by the summer. These "Castle Keep" games became quite popular in Minneapolis in 1974, as contemporary issues of the local fanzine Minneapa document, and many local fans developed their own dungeons, largely unaware of the existence of Dungeons & Dragons. Much as Gygax adventured in Blackmoor with Arneson and then largely implemented his own rules from his experience, so did Fallert build a system for dungeoneering that followed his own subjective impressions as a player. While it seems that Fallert himself was vaguely aware of Dungeons & Dragons, he presented "Castle Keep" to local science-fiction fans in such a way that many took it to be a game of his own invention. In February of 1974, a Minneapolis science-fiction fan named Louis Fallert (better known as Blue Petal) began running a game called "Castle Keep" which he based on his experiences playing in dungeon adventures with the MMSA (Fallert wrote a blurb about this for Alarums & Excursions #3). The great irony of VanGrasstek's Dungeon is that he was unaware of Dungeons & Dragons when he produced it, due to an almost incredible chain of events. Weighing in at eighteen pages, and released late in the summer of 1974, Rules to the Game of Dungeon seems certain to be the second published role-playing game. Fortunately, historians don't need to choose between the two, because Craig VanGrasstek's Rules to the Game of Dungeon (1974) beat them both handily.
One of the perennial questions about the history of role-playing games is this: which came second, Tunnels & Trolls or Empire of the Petal Throne? Deciding between the two is largely a question of semantics, of whether you count various small-run amateur publications as releases or not.