A fantasy sport (also known as rotisserie, roto, or owner simulation) is a game where fantasy owners build a team that competes against other fantasy owners based on the statistics generated by individual players or teams of a professional sport. Probably the Fantasy Sports most common variant converts statistical performance into points that are compiled and totaled according to a roster selected by a manager that makes up a fantasy team. These point systems are typically simple enough to be manually calculated by a "league commissioner." More complex variants use computer modeling of actual games based on statistical input generated by professional sports. In fantasy sports there is the ability to trade, cut, and sign players, like a real sports owner.

The landmark development in fantasy sports came with the development of Rotisserie League Baseball in 1980. Magazine writer/editor Daniel Okrent is credited with inventing it, the name coming from the New York City restaurant La Rotisserie Francaise where he and some friends used to meet and play.[8] The game's innovation was that "owners" in a Rotisserie league would draft teams from the list of active Major League Baseball players and would follow their statistics during the ongoing season to compile their scores. In other words, rather than using statistics for seasons whose outcomes were already known, the owners would have to make similar predictions about players' playing time, health, and expected performance that real baseball managers must make.