Movies based on video games do not have a great critical track record because too often they are made with aspirations for money instead of quality, according to Legendary Pictures' Thomas Tull, producer of the upcoming Warcraft movie based on Blizzard Entertainment's beloved fantasy franchise.

"Doing a video game movie has not really been done well, and I think part of the reason for that is it's been done for the wrong reasons," Tull told IGN. "If you simply say 'How many people have played the game? How much money can we make?' You're doomed. You're doomed right off the start."

Tull, of course, says Warcraft will be different, thanks in part to director Duncan Jones (Moon, Source Code), and the cast he's been able to assemble.

"We hope that when you see the first trailer for it, you're going to say 'OK, this is not what I was expecting.' He's an incredibly exciting filmmaker," Tull said.

Tull is in business to sell you on the idea that the Warcraft movie will be great, but fans will get to decide for themselves when the first trailer is released. Asked when it would arrive, Tull said, "We show up every summer at Comic-Con--we really enjoy it, and the fans seem to enjoy taking a look at things, so I wouldn't be surprised."

Last summer at Comic-Con, Jones showed off a mood piece for the Warcraft movie, though this video has never been published publicly. We've seen an image from the movie's set, but that's it so far. Finally, Tull offered a tease about the plot for Warcraft, suggesting it will closely follow two tribes.

"With a great cast, there's a lot of folks to follow, so I'd look more in that direction because there's so many talented people working on it," he said. "We're very aware of the fact that in the mythology of Warcraft, there are two tribes--two big things to follow. We think you're going to get a chance to look at both."

Tull didn't say more, though it's possible the two groups he's referring to are Orcs and Humans. Jones previously said that the movie would focus on the origin story of the battle between Orcs and Humans.

Warcraft hits theaters in March 2016.

Though movies based on video games don't have a great critical track record, the same can't be said for the commercial opportunity of such films. For instance, the recent Need for Speed movie bombed with critics, but it became profitable in under two weeks.