UKSR

Author: pink404

An ULTRAKILL ranked speedrun mod.

Public matchmaking uses Steam as free infrastructure, but no longer creates a separate Steam lobby for every queue/category. UKSR uses one discoverable Steam matchmaking hub. Queued players publish their category, scope, difficulty and rating as Steam lobby member metadata, then compatible clients deterministically pair with each other inside the hub.

That removes the old create/search/join race between lots of tiny public lobbies. Unrelated users in the hub are filtered out by an internal match ID once a pair is formed.

If nobody is running your exact category but somebody is queued elsewhere, UKSR can offer that queue instead.

Private lobbies still use one UKSR-... code derived from the Steam lobby ID and the Steam friend invite overlay.