The Coming of the Quantum Cats can - given different social conditions - develop completely different character traits (timid or assertive, benevolent or predatory, etc.) The title refers to the famous thought-experiment known as "Schrödinger's Cat", where the outcome of a real-world event depends on a quantum event. By some interpretations, the real-world object, in this case a cat, must be in two states simultaneously until it is observed. However, the story is more closely related to the many-worlds interpretation of quantum mechanics where all possible outcomes of an event occur, each in its own parallel universe. The same concept was treated, somewhat more pessimistically, in
Dead or Alive Ultimate of the same color, a copy of "Dead or Alive Ultimate", and some bonus Kasumi-themed extras. In the United States, two trading cards with character pictures on them were randomly included in each game as part of a collector's edition. The game disc of the North American release also contains the Booster Pack for "Dead or Alive 3", which adds numerous character costumes and a new opening cinematic for the game. This disc also included a G4-produced segment from their "Icons" series detailing the history of the "Dead or Alive" series, along with interviews featuring various people from the video