Learn to Place and Judge Blackjack Side Bets
This guide explains how blackjack side bets work, from the moment the optional wager goes down to the point where it is settled. It is written for players in Ireland who already know the main game and want to understand 21+3, Perfect Pairs and the extra bets on live tables before staking anything. We set out the paytables in common use, what the house edge on each one means over a run of hands, and why the price of a side bet is so different from the hand it rides beside.
What a Blackjack Side Bet Actually Is
A side bet is an optional wager placed alongside the main blackjack hand, settled on its own outcome rather than on whether you beat the dealer. Most of them look only at the first cards dealt: your two cards, and in some cases the dealer’s upcard as well.
That independence matters more than it first appears. A Perfect Pairs bet can win while the main hand goes on to lose, and the reverse happens just as often, because the two wagers share cards but not results.
The two names a player meets most often are 21+3 and Perfect Pairs. 21+3 treats your two cards and the dealer’s upcard as a three-card poker hand, paying on a flush, a straight, three of a kind, a straight flush or suited trips. Perfect Pairs pays when your first two cards share a rank, with the payout rising as the match gets closer: a mixed pair, a coloured pair, then two identical cards, which multi-deck shoes make possible.
Live tables add their own. Evolution’s Infinite Blackjack, for example, carries Any Pair, 21+3, Hot 3 and Bust It, where Hot 3 pays on your two cards plus the upcard totalling 19, 20 or 21, and Bust It pays when the dealer busts, with more paid the more cards the bust takes.
Side bets are settled first.
Placing a Side Bet, Hand by Hand
The mechanics are the same on most RNG and live tables. Here is the order in which a side bet is placed and paid.
- Step 1
Open the help screen first
Before staking, find the game's paytable and rules panel. It lists each side bet, what it pays for every outcome and, on many tables, the theoretical RTP, which is the long-run share of stakes returned. - Step 2
Place the main bet as normal
Most tables require a main wager before a side bet is accepted. Put your chips on the main betting spot first, keeping within the table minimum and maximum shown on screen. - Step 3
Add chips to the side spot
Drop your chosen stake on the 21+3, Perfect Pairs or other side-bet area. Side bets usually carry their own lower limits, and the stake can be smaller than the main wager. - Step 4
Watch the first cards settle
Once the opening cards are dealt, the game checks the side bet straight away. A winning combination is paid at the posted odds; a losing one is collected before you make any playing decision. - Step 5
Play the main hand by strategy
The side bet's result changes nothing about the correct play. Hit, stand, double or split exactly as basic strategy says, since the main hand is settled entirely separately.
What the House Edge Costs You
The house edge is the share of each stake the casino expects to keep over a very long run of bets. On the main hand of a typical blackjack game played by basic strategy it sits around half of one per cent; side bets cost far more.
We checked the published analysis at Wizard of Odds for the common 21+3 paytable of 5:1 on a flush, 10:1 on a straight, 30:1 on three of a kind, 40:1 on a straight flush and 100:1 on suited trips. With eight decks that table carries a house edge of 3.70%. Wizard of Odds also lists weaker 21+3 versions, one of which reaches 7.14% at six decks.
Perfect Pairs at the common 6:1, 12:1 and 25:1 paytable works out at around 4.1% with eight decks and roughly 6.1% with six, according to the figures we compared across several published calculations. For Infinite Blackjack, review sites report Evolution’s side-bet RTPs as 95.90% for Any Pair, 96.30% for 21+3, 94.60% for Hot 3 and 94.12% for Bust It, though we could not confirm those on an Evolution primary page.
Put that into money. Staking €2 on 21+3 at 3.70% over 500 hands means €1,000 wagered and an expected cost of about €37, against roughly €5 for the same €1,000 on a main hand at half a per cent. That is a long-run average, not a forecast for any session; a short run can land a 100:1 payout or nothing at all.
21+3 Against Perfect Pairs
These are the two side bets found on most blackjack tables. The rows below compare them on the common paytables described above.
21+3 | Perfect Pairs |
|---|---|
| Uses your two cards plus the dealer's upcard | Uses only your first two cards |
| House edge around 3.70% on the common eight-deck paytable | House edge around 4.1% at eight decks, about 6.1% at six |
| Top payout 100:1 for suited three of a kind | Top payout 25:1 for an identical pair |
| Wins on roughly one hand in ten | Wins on roughly one hand in fifteen at eight decks |
| Several paytable versions in circulation, some far weaker | Paytables also vary, including 5:1 on a mixed pair |
Common Myths and Sensible Limits
The most persistent myth is that a side bet is “due” after a long losing streak. Each hand is dealt from a shuffled shoe or an RNG, and past results do not make a pair or a flush any more likely on the next deal.
A second myth runs the other way: that one big payout proves a bet is worth playing. A single session, winning or losing, says nothing about the long-run return, which is fixed by the paytable and the number of decks.
Card counters can sometimes shift the odds on certain side bets in a physical shoe, but online RNG games reshuffle every hand and live continuous shufflers remove most of that effect, so for an online player the posted house edge is the price.
If you enjoy side bets, treat them as entertainment with a known cost. Keep the side stake a small fraction of the main wager, set a session budget before you sit down, and use the deposit limits and time-outs that licensed operators provide. Support for anyone in Ireland worried about their gambling is available from the HSE’s problem gambling services and from GamCare’s helpline.
The paytable decides everything.
Related Terms
Blackjack Side Bets: Common Questions
Do I have to place a side bet to play blackjack?
No. Side bets are always optional, and the main hand plays exactly the same with or without them. Most tables do require a main wager before a side bet is accepted.
Does a side bet change how I should play my hand?
No. The side bet is settled on the first cards, before any decisions are made, so basic strategy for the main hand stays exactly as it was.
Which blackjack side bet has the lowest house edge?
On common paytables, 21+3 at 3.70% with eight decks usually comes out cheaper than Perfect Pairs. The figure depends on the exact paytable and deck count, so check the help screen.
Can a side bet win if my main hand loses?
Yes. The two wagers are independent. A Perfect Pairs bet can pay on a pair of eights even if the main hand then busts or loses to the dealer.
Why does the number of decks matter for Perfect Pairs?
More decks make an identical pair more likely, which changes the return. With the common 6:1, 12:1, 25:1 paytable, the house edge is roughly 4.1% at eight decks and 6.1% at six.
Is insurance a side bet?
In effect, yes. Insurance is offered when the dealer shows an ace and pays 2:1 if the dealer has blackjack, but basic strategy advises declining it.
More about online casinos
What we check first is step one, because the same side bet name can carry quite different paytables from one table to the next. A 21+3 paying 30:1 on three of a kind returns noticeably more than one paying 25:1, and the label on the betting spot will not tell you which you are facing.