In the 1970s, a group of gaming friends added the concept of role-playing to the previously straightforward play of war games. Gamers Gary Gygax and his associate Jeff Perrin published instructions for Chainmail, a medieval war game, in 1971. This game differed from all other published war games by including a fantasy supplement based in part on the increased cultural interest in the works of fantasy authors such as J.R.R. Tolkien and Robert E. Howard, author of the Conan series. Chainmail’s publishers, somewhat defensively, wrote, “Special features include rules for jousting wizards, trolls, hobbits and (why not) dragons, among others.”
Before 1971, Gygax was a member of the Castle and Crusade game society, which utilized his medieval setting, the “Great Kingdom,” for war games. Fellow gaming enthusiast Dave Arneson joined the society and developed a modified city and castle scenario within that setting. When Chainmail was published, Arneson used those rules for a modified campaign as a Chainmail variant, which included a dungeon of several levels beneath the castle. And Gygax, playing Arneson’s game, enjoyed it so much that he asked Arneson to write down the rules for him. Working with approximately 20 pages of notes from Arneson, Gygax tried, in 1973, to put the game instructions and layers of complexity in layman’s terms and in the process developed the outline for Dungeons & Dragons.