# World Sync

Fallout 4 assumes a single player owns the world state. Multiplayer requires deciding which client or server controls each piece of world state.

## Implemented (MVP)

Host-authoritative time and weather sync is implemented via the `worldState`
packet. See [`world-state.md`](world-state.md) for the field spec.

- Host: tracked by `worldStateHostPlayerId` (first connected client; reassigned to lowest remaining `playerId` on host disconnect)
- Synced fields: `gameHour`, `gameDaysPassed`, optional `weatherFormId`
- Weather apply: exterior cells only on non-host clients
- Server: pass-through relay with host-only send guard

## World State Examples

World state can include:

- Doors
- Containers
- Pickups
- NPC deaths
- Physics objects
- Quest stages
- Workshop objects
- Terminal states
- Dialogue state

## Early Approach

The first prototype should avoid world sync as much as possible.

Recommended early restrictions:

- Use a custom test cell
- Avoid lootable containers
- Avoid quests
- Avoid doors
- Avoid terminals
- Avoid persistent world changes

## Later Ideas

Possible future approaches:

- Host-controlled world state
- Server-authoritative world state
- Cell-specific state tracking
- Limited interaction whitelist
- Resettable test environments