Basic strategy guide
Start with the core decision framework.
What S17 means
S17 means the dealer stands on all 17s, including soft 17. A soft 17 is a hand totaling 17 that contains an ace being counted as 11, such as Ace-6.
What H17 means
H17 means the dealer hits soft 17. The dealer must take another card on Ace-6 and any equivalent soft-17 combination. The dealer may improve the hand to 18 through 21, remain on a soft total, or bust after additional cards.
Why H17 is generally worse for the player
Allowing the dealer to hit soft 17 gives the dealer another opportunity to improve a relatively weak total. Although the dealer can also bust, the rule generally increases the house edge compared with an otherwise identical S17 game.
The exact effect depends on the rest of the rules, so it should be evaluated as part of the complete table rather than in isolation.
Strategy decisions that can change
Some doubles and surrender decisions can change between S17 and H17. The exact differences depend on deck count and other rules. This is why copying a single chart without checking the dealer soft-17 rule can produce systematic errors.
How to identify the rule
Casinos often print 'Dealer stands on all 17s' or 'Dealer hits soft 17' on the felt, table placard, game-information screen, or rules page. If the wording is unclear, verify it before choosing a strategy profile.
Related blackjack guides
Strategy charts by rules
Match the chart to the table.
Surrender rules
See where S17/H17 can affect surrender.