Over the next few years, three expansions for the Pocket Box Illuminati game were published-the first two were substantially incorporated into the deluxe edition, while the third was an earlier version of what would become Illuminati: Brainwash. After doing research on the Illuminati and conspiracy theories, and 'extensive and enthusiastic playtesting' it went on the market in July 1982 in the Pocket Box format (a plastic box the size of a mass-market paperback) which was at the time the usual for SJG. He decided 'a game about the secret-conspiracy idea behind Illuminatus!' was doable.
Steve Jackson decided against adapting the novel because of the expense of game rights, and the difficulty of adapting a novel with such convoluted plots. In September 1981, Steve Jackson and his regular freelance cover artist Dave Martin discussed their shared admiration of the Illuminatus! Trilogy, and the latter suggested a game.
