A protected slot machine has a token-type cash device and a smart card reader. A central unit manages the games played by token and/or smart card. Improper use by the players is prevented by separating the credits issuing from games by card or by tokens, respectively. As a result credits are given in the form of tokens for a stake or a game played with tokens and, when a game is played with a smart card, credits are applied to a smart card present in the reader before it is ejected or before the insertion of a new card.