Each blackjack game has a basic strategy, the optimal method of playing any hand. When using basic strategy, the long-term house advantage (the expected loss of the player) is minimized.

An example of a basic strategy is shown in the table below, which applies to a game with the following specifications:[15]

Four to eight decks

The dealer hits on a soft 17

A double is allowed after a split

Only original bets are lost on dealer blackjack

Key:

S = Stand

H = Hit

Dh = Double (if not allowed, then hit)

Ds = Double (if not allowed, then stand)

SP = Split

Uh = Surrender (if not allowed, then hit)

Us = Surrender (if not allowed, then stand)

Usp = Surrender (if not allowed, then split)

Most basic strategy decisions are the same for all blackjack games. Rule variations call for changes in only a few situations. For example, to use the table above on a game with the stand-on-soft-17 rule (which favors the player, and is typically found only at higher-limit tables today) only 6 cells would need to be changed: hit on 11 vs. A, hit on 15 vs. A, stand on 17 vs. A, stand on A,7 vs. 2, stand on A,8 vs. 6, and split on 8,8 vs. A. Regardless of the specific rule variations, taking insurance or "even money" is never the correct play under a basic strategy.[15]

Estimates of the house edge for blackjack games quoted by casinos and gaming regulators are based on the assumption that the players follow basic strategy.

Most blackjack games have a house edge of between 0.5% and 1%, placing blackjack among the cheapest casino table games for the player. Casino promotions such as complimentary matchplay vouchers or 2:1 blackjack payouts allow players to acquire an advantage without deviating from basic strategy.[16]