Although he is supposed to be his self-proclaimed Number One, the Devil doesn't really seem to pay attention to King Dice, sometimes even forgetting who he is, until he tells him that he has captured Cuphead (which is not true). In The Cuphead Show King Dice first appears in 'Roll the Dice' (S1E5). Eventually the Devil is beaten and forced to surrender, leaving him and Dice unable to do evil anymore, or at least for a good amount of time.
Eventually he loses the bet and his favor with the Devil after Cuphead and Mugman defeat him, with the Devil offering them to take Dice's former spot. Eventually Dice and the Devil make a bet over whether the Cup Brothers will return successful or fail in the process where Dice bets against them making it. He and his boss send Cuphead and Mugman (who'd gotten themselves indebted to the Devil) to collect the Soul Contracts of the Runaway Debtors so they can be freed of their debt. In the game, King Dice is the Devil's right-hand man and the manager of his casinos.
