The Ultimate Guide to Playing Soft 18 in Blackjack

Updated on May 12, 2025

What Is a Soft 18 in Blackjack?

One of the hands that blackjack players often misplay is soft 18, especially when facing a dealer's 10 upcard (soft 18 vs 10). This is a hand that totals 18 and contains an ace counted as 11. Examples of soft 18 hands are: A-7 or A-3-4.

The reason these hands are classified as "soft" 18 is because the strategy for playing them is different from a hand that totals 18 and either doesn't contain an Ace (e.g., 10-8), or if an Ace is present, it's counted as 1 (e.g., 5-9-A-3). These latter examples are known as "hard" 18 hands.

A soft 18 gives you flexibility that a hard 18 doesn't provide. Since the Ace can be counted as either 1 or 11, you can hit a soft 18 without risking a bust. This versatility is what makes the strategy for playing soft 18 unique and often misunderstood by casual players.

Playing Options for Soft 18 in Blackjack

When you are dealt a soft 18, you have three playing options:

• Double Down
• Hit
• Stand

Which option is best depends on three critical variables:

• Whether the soft 18 hand is composed of two or more cards
• The number of decks of cards you are playing against
• Whether the rules specify the dealer must hit their soft 17 (h17) or stand (s17)

Optimal Soft 18 Strategy for Multi-Deck Games

Double and Multi-Deck Games with S17 Rules

In double- and multi-deck games where the dealer stands on soft 17 (s17):

• If dealer shows a 3, 4, 5, or 6, you should double down
• If the dealer shows a 2, 7, or 8, you should stand
• If dealer shows a 9, 10, or Ace, you should hit (with one exception we'll cover later)

Double and Multi-Deck Games with H17 Rules

If the rules specify that the dealer must hit soft 17 (h17), follow the same strategy as above, but with one key difference:

• You should also double down against a dealer's upcard of 2

Soft 18 Strategy for Single-Deck Blackjack

Single-Deck Games with S17 Rules

In single-deck games, where the dealer stands on soft 17 (s17):

• If dealer shows a 3, 4, 5, or 6, you should double down
• If the dealer shows 2, 7, 8, or Ace, you should stand
• If the dealer shows a 9 or 10, you should hit

Single-Deck Games with H17 Rules

If the rules specify that the dealer must hit soft 17 (h17) in a single-deck game:

• Hit against a dealer's Ace (rather than stand)
• Otherwise, follow the same strategy as single-deck S17

Why Hitting Soft 18 vs 10 is the Correct Play

Many players automatically stand on any 18, but this is a costly mistake when holding soft 18 vs a dealer's 10 upcard. Let's look at the math in a six-deck game with S17 rules. Excluding tied hands:

• If you stand, you'll win 41% of the hands and lose 59%
• If you hit, you'll win 43% of the hands and lose 57%

Notice that you will lose more hands than you'll win, regardless of what strategy you use. However, you win 2% more hands and lose 2% fewer by hitting soft 18 against a dealer's 10 upcard versus standing, for a net gain of 4%. This makes hitting the better strategy.

When to Stand on Soft 18

Standing is often the best play with soft 18 when:

• The dealer shows a weak card (2 through 8, depending on game rules)
• You're playing single-deck blackjack against a dealer's Ace (with S17 rules)
• You have a multi-card soft 18 (explained below)

The reasoning behind standing on soft 18 against mid-range dealer cards is that the dealer has a higher chance of busting, making your 18 a strong hand.

The Multi-Card Soft 18 Exception

When Doubling Down Isn't an Option

When you are dealt a soft 18 containing three or more cards, doubling down is not allowed in most casinos. For example, if you are dealt a 3 and a 4 and the dealer's upcard is a 6, then you hit and draw an Ace, giving you a soft 18. The playing rules in most land-based and online casinos prohibit you from doubling down.

With a multi-card soft 18, you should:

• Always stand against a dealer's 3 through 6 upcard
• Stand against a dealer's 2 upcard if the rules are h17
• In double-deck games with S17 rules, stand on your multi-card soft 18 rather than hit against a dealer's Ace

Other Doubling Restrictions

The rules in some casinos let players double down in blackjack only on hard hands (prohibiting doubling on soft hands). Additionally, most video blackjack games in land-based casinos don't allow doubling down on soft hands.

The bottom line is:

• If you have a multi-card soft 18, or the rules don't allow soft doubling, always stand instead of doubling when the dealer's upcard is 3 through 6 (with S17), or 2 through 6 (if H17)

Complete Soft 18 Strategy Chart

For quick reference, here are the optimal strategies for playing soft 18 in various game conditions:

Double-and Multi-Deck If Rules Specify S17

*But stand if Double-Deck and multi-card soft 18.

Double-and Multi-Deck If Rules Specify H17

Single-Deck If Rules Specify S17

Single-Deck If Rules Specify H17

Note: Ds means double down if allowed; otherwise, stand. S means Stand. H means Hit. S17 means the dealer must stand on soft 17. H17 means the dealer must hit soft 17.

Soft 18 Blackjack Quiz

To be sure you have the strategy down pat for playing a soft 18, decide how you would play the following hands against the indicated dealer’s upcard. (Assume a double- or multi-deck game with s17 unless otherwise indicated.)

Conclusion: Master Your Soft 18 Blackjack Strategy

Knowing the correct blackjack strategy for playing soft 18 in various situations can significantly improve your blackjack results. Remember that the optimal play changes based on the number of decks, the dealer's upcard, the dealer hitting or standing on soft 17, and whether your soft 18 consists of two or more cards.

By following the strategy tables above, you'll make the mathematically correct decision every time you're dealt a soft 18. While you won't win every hand, you'll maximise your winnings and minimise your losses in the long run.

For the complete basic playing strategy for any set of playing rules, consult Chapter 3 in the Ultimate Blackjack Strategy Guide.

Originally published in December 28, 2016