What other game is comparable to Theatrix but uses playing cards as its randomiser?
Theatrix (role-playing game): Theatrix is a role playing game produced by the defunct Backstage Press and no longer in print. Theatrix (role-playing game):  Primarily diceless, the game includes rules for using dice to resolve actions. Diceless role-playing game:  The style of game is known as "diceless" because most games use dice as their randomiser; some games such as "Castle Falkenstein" use other randomisers such as playing cards as substitutes for dice, and are not considered "diceless".
Castle Falkenstein