Gambling terms, explained straight

Not to be confused with the ace card itself, which can count as 1 or 11 in blackjack.

Casino & Table Games

Splitting aces in blackjack

Splitting aces is the blackjack move of turning a pair of aces into two separate hands, each backed by its own bet.

Common rule
Each split ace receives only one additional card; a 10-value card after splitting counts as 21, not a blackjack.12
Resplitting aces
Allowed in some variants; reduces the house edge by about 0.03%.3
Hitting split aces
Allowed in some variants; reduces the house edge by about 0.13%.3

Key points

  • Splitting aces requires an additional bet equal to the original wager on the second hand.1
  • Under standard rules, each ace gets exactly one card and cannot be re-split or hit.1
  • A hand of ace plus a 10-value card after splitting is paid as 21, not as a blackjack.2

Where this term is used

Not the same as

  • Blackjack rules ace — the value of an ace in blackjack (1 or 11), not the action of splitting a pair of aces
Casino games Blackjack The card game in which splitting aces is a permitted move. Casino games Insurance blackjack A side bet offered when the dealer shows an ace, distinct from splitting aces. Casino games Basic strategy blackjack The mathematically optimal play chart that always recommends splitting aces. Casino games Blackjack strategy card A printed reference showing when to split aces and other pairs. Casino games Blackjack rules dealer Dealer procedures that affect how split aces are resolved. Casino games Blackjack 21 Another name for the game itself, where splitting aces is a standard rule.

Sources

  1. Blackjack en.wikipedia.org Provides the definition of splitting aces and the common rule that each ace receives only one card.
  2. Blackjack wizardofodds.com Confirms the rule that a 10-value card after splitting aces counts as 21, not blackjack.
  3. Blackjack Rule Variations wizardofodds.com Gives the house-edge changes for resplitting aces (0.03%) and hitting split aces (0.13%).

Sources are drawn from regulators, universities and published research, and each one is labelled with what it actually is — a preprint is not called a paper. Bookmaker and affiliate pages are never cited here, because a page that sells betting is not a neutral authority on it.

Written and maintained by Ellis Warrender, writer and maintainer.

Last updated 28 July 2026. Spotted an error? Tell me and it gets fixed and logged on the corrections page.