George R. R. Martin by Victor Milán, in Albuquerque, New Mexico; the players were science fiction writers, including Gail Gerstner-Miller, Milán, John J. Miller, Melinda M. Snodgrass, and Walter Jon Williams, and Martin served as gamemaster. Because of the amount of time and creative energy put into the campaign, Martin initially thought to write a novel on his character, Turtle. However, he realized this would have "rescued one character from [the] SuperWorld campaign, but would have meant discarding all the rest". Since the game had been built by a group, he felt it should be a shared universe anthology, which were popular at the time. Martin invited other writers he believed would be interested in the universe, including Roger Zelazny, Lewis Shiner, Pat Cadigan, Howard Waldrop, Edward Bryant, and Stephen Leigh. Martin said that the group loved comic books and superheroes but wanted to approach the material in a "grittier, more adult manner than what we were seeing in the '80s". He cited the series' "sense of history" as a strength and expressed frustration with the retroactive continuity of mainstream comics. Martin also felt that the multitude of sources for superpowers in comics strained suspension of disbelief when taken together, and he believed a single plausible source was needed. Snodgrass suggested a virus, which allowed for the superpowered Aces, the "monsters and freaks" Jokers, and a high death toll. Snodgrass and Martin also developed the card based terminology, and Milán developed the pseudoscience of the series. The series was originally meant to be set in a then contemporary 1985, but Waldrop, who was to write the first story, insisted that his story take place right after World War II. This created a forty-year gap between the first chapter and the remaining stories, pushing later contributions to fill in the intervening decades. Martin noted that this forced the authors to write about events they would have otherwise ignored, particularly the House Un-American Activities Committee and the McCarthy hearings which gave rise to characters and plot points that "added immeasurable richness to our world and depth of our characters". Waldrop's story also forced Williams to rewrite a new story, "Witness", which became the only shared world story to appear on the final ballot for a Nebula Award. British writer Neil Gaiman met with Martin in 1987 and pitched a Wild Cards story about a character who lives in a world of dreams.