A house edge in blackjack is 1.5%, meaning for every 20 hands played, the house will win about 13 hands. In the event of a tie, the house edge changes to 3.125%.
So, if two players each have 18 hands and both players come up with the same total of 21, then the house would win 4 hands (two 21s and two 18s). If one player has 18 and the other has 19, then the house would win only 1 hand (an 18). In all cases, however, if both players have 21, then the player with the higher total would win.
