As in the typical 3-card poker, it's player versus dealer, except that in this one the player can play several hands. Ante up for each of the hands and then choose whether to make that important side bet.
Once you see your cards -- one hand at a time only -- you can decide whether to stay or fold. If you fold, your bet is forfeit. If you stay, your ante bet must be doubled. If the dealer's hand is lower than queen-high, that's an automatic win. Wins are doubled if dealer qualifies.