From the Manufacturer
One player takes on the role of the escaped student. He is the Human player, and he is trying to rescue his friends and escape Innsmouth. By playing movement cards, he moves his pawn around the board to visit various locations, fights any Deep Ones there, then searches those locations for his friends and equipment to help in their escape. The other players play groups of Deep ones. They are trying to prevent the Human player from escaping. The Deep one players take turns moving their pawns around the board trying to trap the Human. Certain locations on the board also allow them to draw cards, spawn additional Deep Ones or even summon a terrible Shoggoth.
In the summer of 1926, a Miskatonic University field trip goes horribly awry when the students and faculty find themselves in the shadowy, monster-infested town of Innsmouth! Now, held captive by the fiendish, fish-like Deep Ones, who mean to sacrifice them to their watery god Dagon, their fate rests with a lone student - and he's not leaving without his friends! In the Innsmouth Escape board game, one of the players takes on the role of the escaped student, while the other players play groups of Deep Ones trying to prevent the Human player from escaping.