The rule variation of “dealer stands on soft 17” affects blackjack strategy by altering players' optimal decisions when facing a dealer's upcard. When the dealer stands on a soft 17 (a hand that includes an Ace counted as 11, like Ace-6), it generally lowers the house edge, encouraging players to adjust their strategies. Players might be more inclined to stand on lower totals against a dealer's weak upcard, as the dealer is less likely to improve their hand.