Lucky Ladies is a side-bet wager that is offered at some blackjack tables. A blackjack player who places a Lucky Ladies bet wins when dealt two cards that total exactly 20, but loses when the player is dealt two cards that do not total exactly 20. The player is usually allowed to wager between $1 and $25 on Lucky Ladies and a winning player will receive a different payout, depending on the composition of the dealt 20. The payout structure can vary, but this structure is most common:

Non-20 - Player loses original bet
Unsuited 20 - Player wins 4x original bet
Suited 20 - Player wins 9x original bet
Matched 20 (both the rank and suit match) - Player wins 19x original bet
Queen of hears pair - Player wins 125x original bet
Queen of hears pair with Dealer Blackjack - Player wins 1000x original bet

The house edge for this game with 6 decks is 24.71%. The house edge for this game with 8 decks is 24.05% Over 24%! That means that betting on Lucky Ladies is an absolutely awful proposition for the player.

Of course, if you have information about the remainder of the shoe, you might be able to choose better times to wager on Lucky Ladies. That's where card counting can come into play.