Core

RedEngine separates state by owner:

• GameInstance owns application services and survives map travel;
• World wraps one Fusion simulation and scene set;
• GameModeBase owns authoritative match and player rules;
• Actor and ActorComponent own replicated entity behavior;
• subsystem collections own shared services for a game instance or world.

Execution model

• Authority — State Authority spawns and destroys network actors and authors their state.
• Prediction — Input Authority may simulate prediction-safe actor behavior inside Fusion ticks.
• Replicated — actor properties, controller/character ownership, and match state.
• Local only — application UI, audio, camera, and other presentation services.

Create and destroy network actors through World so they remain attached to the correct runner:

Chest? chest = World.SpawnActor(chestPrefab, position, rotation);
chest?.Destroy();

Use GameInstanceSubsystem for services that survive travel and WorldSubsystem for services bound to one simulation. Never keep a world subsystem after travel.

Detailed guides:

• GameInstance, Travel, and Bootstrap
• GameMode Pipeline
• Subsystems

Next: Networking.