Legend tells that Pandora's box unleashed all the evils of mankind, but in reality, it is a weapon of ultimate destruction. The Council of 98, a secret order, hid it so well that its existence was forgotten. This lasted until a team of archaeologists found the box at the bottom of the ocean and placed it in a museum in New York.

The player takes on the role of Charles Deckard, a professional art thief. Hired to steal the box, he mistakenly opens it, releasing horrors upon the world. Now hunted by "The Black Order," he must undo his mistake.

Legendary is a first-person shooter where Deckard fights these creatures with various weapons and uses a life force called Animus Vitae to heal himself and repel enemies. The game also features a multiplayer mode for up to 8 players, pitting rebels against Black Ops and AI-controlled mythical monsters.