Esports are growing substantially. Just take a look at the Overwatch League: Last month, OWL opened its new season to 13 million viewers, a 30 percent increase year over year. The league has also added eight more teams, a larger prize pool of $5 million, and more remote events.

But let’s back up a second, what makes an esport anyway? While any video game could be turned into a professional competition with enough effort, a couple of factors consistently contribute to a good esport.

Community: If a game already has a strong community, it already has a built-in audience. For that reason, it helps if a game is free to play, meaning more people have played it and are familiar with it to begin with.

Spectator Appeal: Viewers should be able to understand the rules and appreciate professional players’ skills without having had to play the game first. In other words, these characteristics lend themselves to spectator appeal. Pro football bent itself to fit the conventions of television with the SkyCam, and poker rose to fame with the introduction of the “hole cam.”

If you really think about it, there’s nothing “special” about throwing one round ball through a hoop and kicking a slightly smaller round ball into a net. They’re all sports at the end of the day, and much like esports, basketball and soccer are appealing, because they fit the two categories of community and spectator appeal.

It’s important to remember that the current crop of popular sports today are different than they were 100 years ago. When viewed through that lens, the future of esports can be far more varied than what we’re currently seeing today.

In fact, we’re already seeing the weird and wonderful world of esports start to bloom. Competitive gaming isn’t just limited to multiplayer online battle arena (MOBA) titles such as Dota 2 and League of Legends. Farming simulators are getting into esports as well. Last month, Twitch hosted a competitive esports event to celebrate the third anniversary of Stardew Valley’s release, complete with commentators and $15,000 in prize money. And earlier this year, developer Giants Software announced that Farming Simulator would be getting its own full-fledged esports league with a total prize pool of up to €250,000 (about $280,000).

Walk away with this buff: What defines an esport has less to do with things like genre and more to do with action. Also, notice that none of the factors that make a good esport are device-specific. To really grow, an esport needs to have money at stake, presenting an opportunity for brands to look at smaller titles they can grow organically like Divekick, Frozen Synapse, and Towerfall—all indie games that are now esports.

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