The Mine Trap hold 8 people. The Parlor and the Travel Room each hold 6. Just a note that the Travel Room and The Parlor both require in-room parent supervision for players younger than 16.
The max is six for the one we did and there was plenty of room and puzzles for us to work on simultaneously.
I don't know for sure but we had five comfortably. The room we did was good for i would think six. You could work on multiple parts of the puzzle simultaneously.
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