Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Arena Football League (AFL) was an indoor American football league founded in 1987 by Jim Foster. It was played indoors on a smaller field than American football, resulting in a faster-paced and higher- scoring game. The sport was invented in the early 1980s and patented by Foster, a former executive of the United States Football League and the National Football League.