A new report conducted by research firm Newzoo has found that 84 percent of U.S. sci-fi MMO gamers play free-to-play titles, rather than subscription-based MMOs.

The study shows that 14 million U.S. gamers play MMOs that have a sci-fi or space theme such as Eve Online -- 36 percent of the overall 39 million MMO players in the U.S. -- and the majority of these people play free-to-play games.

In comparison, 68 percent of U.S. sci-fi MMO players choose to play only free-to-play titles, and do not play any pay-to-play MMOs at all.

Popular free-to-play MMOs include S4 League, Anarchy Online, RF Online and Planet Calypso.

Sci-fi MMOs are less popular in Europe and emerging markets, however, with 27 percent of European MMO players choosing to play sci-fi games, and 26 percent in emerging countries.

Peter Warman, CEO at Newzoo, noted, "You will not catch me making any predictions about Star Wars: The Old Republic."

He continued, "I am very curious to see how many free-to-play sci-fi gamers EA will be able to convert to P2P gamers and what part will come from outside the current pool of sci-fi gamers, being complete newcomers as well as the subscribers to Eve Online, WoW, Rift or any other AAA P2P MMO game."