The world of role-playing games began in the 1970s. The game "Dungeons & Dragons" (D&D) was a further adaptation of Gary Gygax's earlier medieval war game "Chainmail." D&D added role-playing; players were now free to imagine the settings, characters, and events that were happening. Other companies followed TSR, the publisher of D&D, and soon the world of role-playing games began to grow. Many still carried medieval themes, but others focused on different subjects, such as space travel or vampires. The trend boomed in the 1980s and '90s, and, most importantly, began to influence computer game design as well. Game designers quickly learned that computers were ideal platforms for role-playing games and many of the classics can now be played as part of a MMORPG--a Massively Multiplayer On-Line Role Playing Game. Role-playing games, and Dungeons & Dragons in particular, were criticized by some over the years. But these games changed the nature of play for older children and adults and the world of play has not been the same since. Dragonlance is an incredibly popular shared universe created by Tracy and Laura Hickman. It spans novels, video games, an animated movie, and a series of D&D-style role-playing games. Dragonlance is especially famous for its detailed geography and extensive timeline.