6-5 Blackjack is a type of blackjack that casinos offer with a major rule change that greatly benefits the casino to the detriment of the player. The rule change is that blackjack pays 6 to 5, rather than 3 to 2.

So for a $100 bet, a player with blackjack on a 6-5 table will only receive $120, compared with $150 on a regular table. That's a difference of $30 per $100 for every blackjack dealt! Another way to look at the rule is in terms of house edge. The house edge increases about 1.39% in 6-5 blackjack. That means the house will win on average $1.39 more for every $100 wagered.

This rule adjustment is most commonly seen at the single-deck blackjack tables to discourage potential card-counters from taking advantage of typically otherwise favorable conditions. This seemingly minor rule change, however, tilts the 6-5 single-deck tables highly against the player.

So never play 6-5 blackjack!