Every week when players log in to Overwatch, it should feel fresh and different.

That’s the dream Principal Game Designer Scott Mercer has for Overwatch—and, starting in Competitive Season 21, it’ll become a reality. With the introduction of Hero Pools, a rotation curated by the Overwatch team will be available in Competitive Play, and one tank, one support, and two damage heroes will be unavailable from the roster each week with the intent to keep the meta fresh and encourage hero diversity in matches.

Interested in the philosophy behind the newest change to Competitive play? Mercer provided some insight into how Hero Pools will shake things up in Season 21.

Where did the concept of Hero Pools come from?

Scott Mercer: We get feedback from our players about how the meta doesn’t change often enough. Especially at the highest ranks of the game, like Master and Grandmaster, we’ve seen the meta become more defined. The better you are at the game, the more you start to see the effects of what players deem are the strongest heroes.

Even after our decision to switch team compositions to 2-2-2, creating change in the meta is a hard thing to do. We started being more aggressive with hero balancing with the hope that it would affect the meta, but we still worried that it wouldn’t shift enough for players. Hero Pools are part of a solution to address players’ desire to have a constantly shifting meta.

What do Hero Pools bring to Overwatch players?

Every week when players log in to Overwatch, it’ll be a slightly different game. There’ll be more variety. What we’re trying to address is the feeling that the game isn’t changing rapidly enough. This is one part of—along with more aggressive balance changes—helping make Overwatch an ever-evolving game.

A lot of players find an ever-evolving game more exciting. They don’t want to play the same heroes and compositions every time. When they feel like the meta gets more static, it’s not as fun for them. We’re trying to do this to make our game more enjoyable to both play and watch.

How long will heroes remain out of rotation?

We don’t want to have a hero be out of rotation for a long time, so you won’t see any unavailable for more than two weeks in a row. Also, when we make significant balance changes to a character, we don’t want to make them unavailable—we want players to be able to see how those changes affect the game.

Does the Hero Pool system work differently for the Overwatch League?

While we have control over the Hero Pools for online players, the Overwatch League Hero Pools are slightly different. In the Overwatch League, analysts will look at the previous two weeks of hero play data, and if a hero is played more than 10 percent of the time, they’re eligible to be taken out of the rotation.

For example, from all of the tanks that are played more than 10 percent of the time during weeks three and four, one will be randomly chosen and taken out of rotation for week five. The same will happen with two damage heroes and one support hero.

Since the heroes being taken out will be the most used, I don’t know if you’ll ever see someone like Torbjörn taken out of rotation. But you never know!

Why Hero Pools and not a system where players can ban characters of their choice?

We just didn’t think it was the right fit for Overwatch. We didn’t want to turn the pre-match phase into something where you have to spend five minutes staring at UI and hero portraits and listening to people argue about the heroes they do or don’t want. But we looked at pick-ban systems and asked, “What do they provide?”, and what do we want to accomplish?

They provide motion and help shake up the meta, which is what we want, so we came up with the idea—I think it’s something that [Overwatch Game Director Jeff] Kaplan originally pitched—what if we made certain heroes temporarily unavailable?

How do you pick heroes to ban while maintaining a balance between players of different skill levels?

It’s always difficult. When we look at these things—low SR (skill rating) vs. high SR vs. professional play—there are a lot of different factors there. We want to mix it up. Some weeks might not affect the highest level of play that much, and some weeks will. We’re not relying on Hero Pools alone to change the meta—it’s a tool for us to use, and we’ll adapt to things as they change.

There are still a lot of unknowns regarding game balance. It’s one thing to say, “hey, here’s this concept of a thing” and another to actually live with it. We have a lot of flexibility—if we need to take more or fewer heroes out of rotation, we’re not fixed into one tank, two damage, one healer. How often pools change isn’t fixed. We want to work with the community to see how things go.

How will players know which heroes are out of rotation for the week?

We’ll tell you in-game when the Hero Pool changes. That way, if you’re someone who’s like, “man, I really love Mercy” and Mercy happens to be out of the rotation for a week, we’ll let you know. In that case, you can go play Quick Play, try a role you haven’t before, or learn a new hero—that’s always, y’know, a cool option.

Season 21 is live right now on Windows PC, Nintendo Switch, PlayStation 4, and Xbox One, so power up your favorite gaming machine and join the fight. We’ll see you on the battlefield!