Overview of Game Center groups
In the context of Game Center, a group is two or more apps that share leaderboards and achievements. The purpose of adding an app to a Game Center group is to share data, specifically to share leaderboards and achievements. When you add an app with existing Game Center assets to a group, you decide which of the app’s leaderboards and achievements are retained as part of the group. App Store Connect guides you through this process by presenting only compatible assets and options at each step.
You can define leaderboards and achievements for a group in two ways:
Define leaderboards and achievements for an individual app; then, when you move the app to a group, you specify how the app leaderboards and achievements are merged with the group leaderboards and achievements.
Add an app to a group that already has leaderboards and achievements defined. The app uses the existing group leaderboards and achievements. Like apps, groups can organize leaderboards into sets. If a group uses leaderboard sets, apps you add to the group either already use leaderboard sets or can’t have any leaderboards defined.
While an app can only belong to one group, there’s no restriction on the type of apps that can belong to a group. For example, you can create a group containing iOS and macOS apps that share the same leaderboards and achievements. There’s no limit to the number of groups per account or to the number of apps that can belong to a group.
When you’re ready to release a version of an app that’s part of a group, you determine which of the group leaderboards and achievements go live with the app. In addition, you set the app’s multiplayer compatibility options to include the other apps from the group. Visit Distribute a Game Center app.