Common blackjack rule variations explained
Blackjack games vary significantly between casinos. Small rule changes can add or remove several tenths of a percent from the house edge. Knowing what to look for helps you find better games.
Rules that favor the player
S17 (dealer stands on soft 17) reduces the house edge by about 0.2%. Late surrender availability saves around 0.08%. Being able to double on any two cards (not just 9, 10, or 11) saves roughly 0.2%. Re-splitting aces and doubling after splits also help. Fewer decks reduce the house edge — a single-deck game has a lower base edge than an 8-deck game, though casinos often offset this with worse rules elsewhere.
Rules that hurt the player
A 6:5 blackjack payout instead of 3:2 is the most damaging rule variation — it adds about 1.4% to the house edge on its own. Always check the blackjack payout before sitting down. No surrender, restricted doubling (10 and 11 only), and inability to re-split are smaller negative rules but they add up. The combination of H17 and 6:5 payouts makes a game barely worth playing at standard stakes.