Unfathomable

About this board game

Unfathomable is a 3–6 player board game set aboard the SS Atlantica, with games lasting about 240 minutes. In 1913, the steamship is crossing the Atlantic toward Boston—but nightmares, ominous shapes beneath the waves, and a ritualistic murder reveal that this voyage will be anything but ordinary.

The Deep Ones, led by Mother Hydra and Father Dagon, have targeted the Atlantica. Some players secretly take the role of human-Deep One hybrids, working from within the ship to undermine the humans’ efforts and help send the vessel to the bottom.

Human players must survive the crossing while defending the ship, managing its four crucial resources, and determining which fellow passengers can be trusted. Everyone draws from the same resource pool, creating constant tension: humans try to preserve what remains, while traitors look for opportunities to deplete it without exposing themselves.

• Fend off the Deep Ones and protect the Atlantica from excessive damage.
• Manage shared resources while weighing difficult choices.
• Resolve crises through decisions and dangerous skill tests.
• Identify hidden enemies before their sabotage sinks the ship.

At the end of every player’s turn, a mythos card introduces a crisis for the group to resolve. A choice such as Food Rationing may put passengers or resources at risk, while a Hull Leak demands a skill test with potentially disastrous consequences.

During a skill test, players secretly contribute cards to a shared face-down pile. Once shuffled and revealed, helpful skills can secure success—but the wrong contributions can hinder the result. In Unfathomable, every crisis is an opportunity for cooperation, suspicion, and carefully concealed sabotage.