Over the course of this year, we’ve seen several traditional gaming companies trying to figure out a free-to-play model. The latest may be Cryptic Studios, which is reportedly considering the merits of free-to-play for its massively multiplayer game Star Trek Online.

Star Trek isn’t the only brand-name game looking at free-to-play. Earlier in June, Lord of the Rings Online announced that it would become free this fall, relying on a mixture of purchased game expansions and virtual goods to make money.

Although social games on Facebook are obviously successful, their connection to traditional hardcore games isn’t always obvious. So free-to-play MMOs have retained significant differences from their cousins on Facebook — entire sections of the games may require a purchase to open, while dedicated players will often be offered the same sort of simple monthly subscription most MMOs use already.

Figuring out exactly how serious traditional game companies are about using a free-to-play model is also made more difficult by the size of the titles involved; it can sometimes be difficult tell whether move to free play because of genuine faith that it will work, or because of vanishing userbases that force desperate moves.

However, titles like Lord of the Rings Online have the necessary brand cachet to draw in subscribers, so these recent moves seem more significant. LOTRO is also owned by Turbine, which last year made another branded title, Dungeons and Dragons Online, free — and reported much higher revenue to the industry as a result.

Despite Turbine’s success, other MMO makers have said they won’t move to free-to-play anytime soon (most notably Blizzard, the owner of World of Warcraft). But there will be more announcements later this month that could significantly rock the boat for traditional gaming companies, pushing all online gaming further down the road to free.