Manifold TCG is a card and dice game set in a new fantasy-space universe. Docide Underworlds continues the Manifold saga following heroes in discovering Rutherford and Eurus's plan to steal the Locus of the Weave. The expansion is set in the free city of Docide on the moon overrun by outlaws due to distance from the planet Tyryn.

It introduces 192 new cards including 32 new heroes. Each booster contains 1-2 heroes 2 rare cards 6 uncommons and 15 commons; the boosters are not randomized and are designed to be opened and shuffled together in pairs for expansion play.