^{THE BETS OFFERED IN CRAPS}

^{The Dicedealer.com online textbook}

A buy bet is a place bet that will pay true odds, however only recommended on 4 and 10. The bet is for the chosen number (4 or 10) and against the 7. 

1 of  3 things can happen with this bet:

1) The selected number (4 or 10) is rolled and the bet wins.
2) A 7 is rolled and the bet loses.
3) Any other number is rolled and the bet neither wins nor loses but rolling continues.

A Buy bet is similar to a Place bet except that you pay a 5% vig up-front in exchange for receiving a true payoff if it wins. The vig is figured on the amount wagered. For example, if you wanted to make a $20 Buy bet on the number 4, you'd put down $21 in the Come area and tell the dealer "Buy the 4". He or she will move $20 to the number 4 point box and place a BUY button on top it. The extra $1 (5% of $20) is the vig for the house. The result is that you'll win $40 (2 to 1) instead of $36 (9 to 5). If you do win and want to keep your Buy bet up, you'll have to pay the dealer another vig. The vig is returned if you remove the bet before it wins or loses.

Depending on how much you bet, the vig may work out to a fractional amount. If this fractional amount is not fully payable with any of the available checks, then the vig is rounded off. Generally, when the vig amount falls halfway or less between two payable amounts, the vig is rounded down, otherwise it's rounded up. So at a table where the smallest checks are $1, the vig will be rounded down on fractions of .50 or less and rounded up otherwise. e.g. You could Buy a bet for $50 and pay only $2 vig even though mathematically the vig comes out to $2.50. However, if you made two $50 Buy bets at the same time, you'd be charged $5 and not $4 for your total action. Even if you didn't make both bets at the same time, some casinos would charge you the extra $1 when you made the second bet, and some would not. Obviously those that don't collect the extra buck are being a bit more generous. There are some casinos that are even more generous by only charging a vig on those bets that you win. This lowers the house advantage even more and makes the Buy a much better bet. The point to remember is that each casino handles their vigs a little differently.

Buy bets, like Place bets, are automatically OFF on the come-out roll unless you call them ON. They can be called ON or OFF, as well as put up, taken down, increased, or decreased (with vig adjustments) at any time.
Buy bets do not make sense for the 6 or 8, and generally not the 5 or 9 since the equivalent Place bet percentages are already lower than 5%. But for the 4 and the 10 they do make sense and should be utilized instead of Place bets. 
When you make a Buy bet, you're taking odds which is the exact opposite of a Lay bet where you're laying odds.