A buy bet is a craps wager where you bet a box number and receive true odds, but pay a commission, often called vig. Buying the 4 or 10 is often better than placing them, especially if the commission is charged only on wins. The rule matters more than the name of the bet.
Quick Facts
- Buy bets can be made on 4, 5, 6, 8, 9, or 10, depending on house rules.
- They pay true odds before commission.
- The commission is commonly 5%, but procedures vary.
- Buying 4 or 10 is often better than placing 4 or 10.
- Buy 5/9 and Buy 6/8 need careful comparison because the commission can erase the benefit.
- Some casinos charge commission upfront; others charge only on wins.
- Always ask: “Is the vig paid upfront or only on wins?”
Plain Talk
A buy bet is a place-style bet with a different price.
You still choose a box number. You still win if that number rolls before 7. You still lose if 7 rolls first. The difference is payout.
A normal Place 4 pays 9:5. A Buy 4 pays true odds of 2:1, but the casino charges a commission. If the commission is small and charged only when you win, the buy bet can be much better.
This is why experienced players often say: “Buy the 4 and 10, don’t place them.” That advice is usually about math, not superstition.
But buy bets are not automatically good. Commission rules change the edge. A buy bet with upfront commission is worse than a buy bet with commission on wins only. Some tables also have minimum buy amounts or automatic-buy rules at higher bet levels.
For standard payouts and edge comparisons, see the Wizard of Odds craps basics and the Wizard of Odds house-edge appendix. The expected-value derivations are useful for checking commission effects, and the Massachusetts craps rules show how regulated craps wagers are controlled.
How It Works
A buy bet follows the same race as a place bet.
- You choose a box number.
- The dealer books it as a buy bet, not a place bet.
- Your number must roll before 7.
- If it wins, it pays true odds.
- The casino takes commission according to house rule.
- If 7 rolls first, the bet loses.
True odds payouts:
| Buy number | Winning combinations | 7 combinations | True odds payout |
|---|---|---|---|
| 4 or 10 | 3 | 6 | 2:1 |
| 5 or 9 | 4 | 6 | 3:2 |
| 6 or 8 | 5 | 6 | 6:5 |
The key question is commission.
| Commission rule | What it means | Player impact |
|---|---|---|
| Upfront vig | Pay commission when bet is booked | Worse for player |
| Vig on win only | Pay commission only if bet wins | Better for player |
| Rounded vig | Commission rounded to chip units | Depends on bet size |
| Auto-buy | Casino treats certain bets as buys automatically | Can help on 4/10 |
Example: You buy the 4 for $25. True odds pay 2:1, so the win is $50. If the casino charges a $1 commission only on the win, you receive $49 profit. That is usually better than placing the 4 for $25, which would pay $45.
Craps Table Example
You are on a table where buy-bet commission is charged only on wins. The point is 8. You want action on the 10.
You ask the dealer:
“Buy the ten for twenty-five.”
The dealer books a $25 Buy 10.
| Result | What happens |
|---|---|
| 10 rolls before 7 | You win $50 true odds, then pay commission by house rule |
| 7 rolls before 10 | You lose the $25 |
| Any other number | Bet stays working |
If the commission is $1 on a $25 win, your net win is $49. If you had placed the 10 for $25, the normal 9:5 payout would be $45. Buying is better in that scenario.
But if commission were charged upfront and rounded awkwardly, the value could change. That is why the first question is not “buy or place?” The first question is “what is the vig rule here?”
From the Casino Side:
Buy bets require clearer procedure than ordinary place bets because the dealer must know the commission rule and the player must know how the bet is booked.
The base dealer marks or positions the bet according to house procedure. The boxman watches commission handling. The floor may step in when a player says “I wanted that bought, not placed” after the number hits.
Good dealers repeat the call: “Buying the ten for twenty-five.” That creates a clear record before the dice move. This matters because the difference between a $25 Place 10 and a $25 Buy 10 can be several dollars on a win.
From a game-protection view, buy bets create risk in three places: incorrect booking, missed commission, and wrong payout. Surveillance reviews the full sequence, not only the final roll.
Common Mistakes
- Assuming every casino charges buy-bet commission the same way.
- Buying numbers without asking whether vig is upfront or on wins.
- Placing the 4 or 10 when buying would pay better.
- Buying 6 or 8 without checking whether the commission makes it worse than placing.
- Confusing buy bets with odds bets.
- Thinking true odds means no risk.
- Ignoring rounded commission on small bet sizes.
Hard Truth
A buy bet is not good because it sounds smarter. It is good only when the true-odds payout minus commission beats the alternative price.
FAQ
What is a buy bet in craps?
A buy bet is a wager on a box number that pays true odds, with a commission charged by the casino.
What is the vig in craps?
The vig is the commission charged on a buy bet or lay bet. It is often 5%, but house rules vary.
Should I buy the 4 and 10?
Often yes, especially if commission is charged only on wins. It is usually better than placing the 4 or 10.
Is a buy bet the same as an odds bet?
No. An odds bet attaches to a line or come bet and has 0% house edge. A buy bet is a separate box-number bet with commission.
Can I buy the 6 and 8?
Some casinos allow it, but it is often not better than placing the 6 and 8 once commission is included.
Do buy bets stay up after winning?
Usually yes, unless you take them down or the house procedure handles them differently.
What should I ask the dealer?
Ask: “Is the vig upfront or only on wins?” That answer changes the math.
Deeper Insight
Buy bets show why craps cannot be judged by layout labels alone. The same number can have different prices depending on whether it is placed, bought, or taken as odds behind a line bet.
The 4 and 10 are the cleanest example.
A Place 10 pays 9:5. A Buy 10 pays 2:1 before commission. Since true odds are 2:1, the buy bet starts from a fair payout and then subtracts the vig. The place bet starts from a worse payout immediately.
When commission is paid only on wins, the buy 4/10 often becomes much more attractive. When commission is paid upfront, the value is weaker because you pay even when the 7 appears first.
This is also why small-chip rounding matters. If the commission is rounded up too heavily on small bets, the effective house edge can be worse than the headline number.
Formula / Calculation
For a Buy 4 or Buy 10:
P(win) = 3 / (3 + 6) = 1 / 3
P(loss) = 6 / (3 + 6) = 2 / 3
With a $25 Buy 10 paid 2:1 and $1 commission only on wins:
Net win = $50 - $1 = $49
EV = (1/3 × $49) - (2/3 × $25)
EV = $16.3333 - $16.6667 = -$0.3334
House edge:
House Edge = $0.3334 / $25 = 1.33%
Compare $25 Place 10 paid $45:
EV = (1/3 × $45) - (2/3 × $25)
EV = $15 - $16.6667 = -$1.6667
House Edge = $1.6667 / $25 = 6.67%
Formula Explanation in Plain English
The Buy 10 and Place 10 have the same chance to win. The difference is payout. Buying the 10 pays closer to the true risk, then subtracts commission. If that commission is small and only charged on wins, the buy bet is far cheaper than the place bet.
Related Reading
Before using buy bets, read Place 4 and Place 10 so the comparison is clear. For broader context, use place bets explained, craps odds, and craps house edge. You can model the difference with the house edge calculator and expected loss calculator. For bankroll swings, use the variance simulator. If “true odds” makes the bet feel safe, read why low house edge does not mean safe.