A small multiplayer lobby prototype built in Unreal Engine 5 using the Steam Online Subsystem.
This prototype focuses on session creation, joining, and replicated UI behavior.
Features
Steam OSS session creation & discovery
Supports up to 4 players per lobby
Automatic player slot assignment
Replicated player names (Steam display names)
Host displays Start, clients display Ready
Start logic correctly restricted to the host using authority + local player controller checks
Technical Notes
Currently tested using two Standalone Game windows on the same PC (Steam AppID 480).
Map travel is initiated by the host using a server RPC → ServerTravel.
Clients are still being refined to correctly follow the host during map transitions.
Next Steps
Implement proper client travel flow
Add ready-state replication
Add automatic LAN/Steam environment switching in future versions