Blackjack players who claim they were cheated out of tens of millions of dollars by Massachusetts casinos appeared to face better odds in arguments Wednesday before the state’s highest court.

The court heard two class actions claiming that many players were unknowingly steered into a variant where they got a payout of only 6:5 for a blackjack — an ace along with a 10 or face card — instead of the traditional payout of 3:2.

On a $20 bet, that’s the difference between winning $30 versus $24. Over hundreds of thousands of hands, the differential amounts to as much as $30 million a year for the casino operators, the players claim.