About Multiplayer Play Mode
Use Multiplayer Play Mode to test multiplayer functionality within the Unity Editor. You can simulate up to four players (the Main Editor and three Virtual Players) simultaneously on the same development device while using the same source assets on disk. Multiplayer Play Mode can help you create multiplayer development workflows that reduce project build times, run it locally, and test the server-client relationship.
Multiplayer Play Mode terminology
The following have specific meaning in relation to Multiplayer Play Mode:
- Main Editor: The original instance of the project in the Unity Editor. This is the only instance with full authoring capabilities.
- Virtual Players: Simulated players created with Multiplayer Play Mode. These players open in a separate window with limited authoring capabilities when you enter Play mode.
- Players: All player instances, including the Main Editor Player and all Virtual Players.
Limitations
Multiplayer Play Mode has some inherent technical limitations, specifically around scale and authoring.
Scale
The Unity Editor and Virtual Players require a lot of system resources, so you shouldn't use Multiplayer Play Mode at scale. Multiplayer Play Mode is designed for small-scale, local testing environments that can only support up to four total players (the Main Editor and three Virtual Players).
Authoring
Virtual Players have restricted authoring capabilities because they're intended as a vehicle to open multiple project runtimes, not provide a multi-editor authoring workflow. You should use the Main Editor to make changes and the Virtual Players to test multiplayer functionality.
You can't access any Main Editor functionality from Virtual Players.
Performance impact
To reduce the demand on system resources caused by each Virtual Player instance, Multiplayer Play Mode shares specific resources, such as the artifact database and imports between the Main Editor and each Virtual Player.