How many players can play Shift at Midnight?
Shift at Midnight supports up to three players in online co-op - one host plus two friends - and it also plays fully solo if you would rather take the night shift alone.
Co-op size and shape
A co-op session holds three players: the host who runs the shift and up to two friends who join. The three-of-you format fits the game's tense, close-quarters convenience-store setup without overcrowding the space.
The host owns the campaign save, so when friends join they experience the host's shift progression rather than their own.
Playing solo
Single-player is fully supported, so you do not need a group to progress. Many players prefer solo for the pure dread of an empty night shift, then bring friends in for the harder nights.
Solo runs also let you learn the store routine and the tell-tale behaviour of the doppelgangers at your own pace before you add chaos.
Cross-store limits
The three-player cap is the same everywhere, but who you can invite depends on store: Xbox / PC Game Pass players share lobbies, while Steam players are limited to other Steam players (see the crossplay answer).
There is no four-or-more player mode, so plan your group around a trio at most.
Tips for a smooth co-op night
Decide the host up front - the host's save is what advances. Assign one person to run the store computer and cross-check IDs while the others handle the floor and the doors.
Talk out loud: the impostor tells are easier to catch when someone is reading a customer's behaviour and calling it out to the group.