Arguments can be made for nearly any game in the Ultima series being "the best." Certainly, many of the games introduced innovations that are in use today. Ultima II, for example, introduced "moongates" as a means of travel, and cemented the game world as involving an odd mixture of medieval and futuristic technology. Ultima III introduced the idea of a separate combat screen and calculating line-of-sight dynamically to determine what was displayed, as well as the "name? job?" conversation tree that was used through the next three games.