As someone who does research on gender and games, I often hear the conventional wisdom that men prefer to play male characters. For example, that’s Mark Rosewater’s explanation for why there are twice as many male planewalkers as female planeswalkers.

Well, guess what? Conventional wisdom is wrong.

A team of researchers from MSU, led by Robby Ratan, looked at game logs from 18,000 League of Legends players. Unlike many studies on character gender, the research team didn’t have to rely on what people said about the kinds of characters they wanted to play. They could look at what players actually did play. This is important because people often present themselves as they’d like to be seen – even when this doesn’t reflect their real behavior.

During the period of the study, around 70% of available characters were portrayed as male, and around 30% were portrayed as female. That makes 70% male and 30% female the “chance rate” – the distribution you’d expect to see if gender weren’t a factor and people were just choosing their characters randomly. In other words, if men prefer to play male characters, you’d expect to see men choose male-gendered characters more than 70% of the time.

It turns out, though, that men play male characters 70% of the time, and female characters 30% of the time. In other words, male League of Legends players don’t seem to care about character gender. You get the same distribution as you would if they were picking characters at random.

Women, on the other hand, played female characters nearly 50% of the time. Only 30% of characters were female, so this rate is significantly more than what you’d expect if female players were choosing randomly.

In other words, women, not men, are the ones who care about playing characters of their own gender.

This implies that designers should make sure women get plenty of opportunities to play female characters; men, on the other hand, will play whatever they’re given. In other words, worry about women, and men will take care of themselves.

Obviously, things are a bit more complex than that. For example, ability types aren’t randomly distributed across character genders. During the data gathering period, there were no female tanks, but plenty of female support characters. That means that the “pure” gender data is probably distorted by the fact that the male and female character pools aren’t equivalent. Character gender choice is going to be partly influenced by the player’s preferred team role.

Another thing to note is that only 4% of the subjects surveyed were women. That’s an unusually small percentage, suggesting that League of Legends is among the most male-dominated games out there. It could be that men only feel secure playing female characters when the activity is so heavily coded male that it doesn’t threaten their gender identity. Alternately, women might care much more about playing female characters when they know they’re in a tiny minority. That might be because they feel they have to work extra hard to maintain their identity, or because only women with strong ties to their gender identity make it into the community in the first place.

Still, game designers can no longer make the same old lazy assumptions about player and character gender – and that’s got to be a good thing all around.