Relay has the following limitations:

  • Relay is engine agnostic. If you use Relay with Unity, the recommended best practice is to use the Relay SDK, which is coupled with Unity Transport Package (UTP). Relay works with Unity Transport (UTP), giving it the ability to connect clients that might otherwise be unable to communicate because of routing restrictions such as restrictive firewalls.

  • Players can only connect with other players within the same game session. Check out Connection flow.

  • Currently, there is no region-locking functionality; anyone can request an allocation in any region if the region has enough capacity to support the request.

  • The Relay service routes all communication through a single region selected by the host. As a result, cross-region communication might not offer optimal latency.

  • A maximum of 100 players can join the host in the same game session. Not all game types will scale to that high amount of players without the use of a dedicated game server. Carefully consider the impact on the host player when attempting high player count sessions with Relay. This limit's aligned with the maximum number of players allowed in a Lobby.