Ordinary Trials: one to four
You can tackle ordinary Trials alone, or bring a team of two, three or four Reagents. The official game description says mandatory co-op is not forced. A task that is quicker with two players does not automatically make solo play impossible.
Choose the size that fits your group. There is no requirement to fill all four places before entering a normal Trial.
Solo still needs a connection
Solo means that you enter without human teammates. It does not mean an offline campaign. The game’s Steam system requirements include a broadband internet connection, so plan to stay connected even when you play alone.
Do not count every player in the facility as your team
The Sleep Room is a social space, not the ordinary Trial’s party-size limit. Seeing other players there does not expand your team beyond four.
In Invasion, human Imposters can enter a Reagent Trial. They are opponents, not extra co-op slots. Distinguish your Reagent group, the opposing group and how many Imposters can be deployed at once.
Which format should you choose?
- Solo: move at your own pace and practise objective routes without coordinating with teammates.
- Two to four players: share information and tasks, while paying attention to any objectives that scale with group size.
- Invasion: use the dedicated rules for roles and deployment; do not apply the ordinary party count to every character present.