“How much do I lay to win $100?” is the right kind of question at a craps table. A lay bet is not quoted as a simple stake that wins the same amount. You select 4, 5, 6, 8, 9, or 10 and bet that 7 will appear before that number. Because 7 has more combinations than any one of those totals, you risk more than you stand to win.
A separate commission, commonly called the vigorish or vig, gives the casino its advantage. The amount, basis, timing, and rounding of that commission are house-rule questions, not details to guess.
The betting contract
Once booked and working, a lay bet has only two resolving outcomes:
- 7 before the selected number: the lay bet wins.
- Selected number before 7: the lay bet loses.
All other totals are non-decisions. If you lay against 10 and the dice show 5, the wager normally remains in place. The number of rolls can vary; the contest is still “7 or 10 first.”
The fair, or true-odds, prices follow from the number of two-dice combinations:
| Number laid against | Ways to roll the number | Ways to roll 7 | True risk to win |
|---|---|---|---|
| 4 or 10 | 3 | 6 | Risk 2 to win 1 |
| 5 or 9 | 4 | 6 | Risk 3 to win 2 |
| 6 or 8 | 5 | 6 | Risk 6 to win 5 |
Thus, laying against 4 or 10 commonly means risking $40 to win $20 before commission. Against 6 or 8, a true-odds amount could be $24 risked to win $20. The higher win frequency is balanced by the larger loss when the selected number arrives first.
Lay bet and lay odds are not the same wager
The phrases are easy to confuse:
Lay bet: a standalone bet against one box number. It can usually be made without a Don’t Pass or Don’t Come wager. A commission normally applies.
Lay odds: a supplemental true-odds wager behind a winning Don’t Pass or Don’t Come position after a point has been established. It is tied to the line bet and is generally not priced as the same standalone commission bet.
Both risk more to win less because 7 is favored over the point number. Their placement, prerequisites, limits, and commission treatment differ. Calling every dark-side odds wager a “lay bet” can cause a booking error, especially when the dice are about to move.
Commission changes the real price
A lay bet’s mathematical cost cannot be stated accurately until the commission convention is known. Casinos may calculate the charge as a percentage of the amount laid, the amount that can be won, or according to a rounded chip schedule. They may collect it when the bet is made or only when it wins.
Official Massachusetts craps rules illustrate this variation: they permit a percentage up to 5% on true-odds buy and lay wagers and allow collection either when the wager is made or only on winning wagers. The casino must follow its approved method. See the Massachusetts Craps and Mini-Craps rules. A different casino or jurisdiction may use another permitted convention.
That variation explains why two pay tables can quote different effective costs while both describe a lay bet correctly.
Worked example: laying $40 against 4
Assume all of the following:
- you lay $40 against 4;
- the true win is $20;
- the house charges $1, equal to 5% of the possible $20 win;
- the $1 is collected only when the lay bet wins;
- there is no extra rounding.
Among resolving combinations, 7 has six ways and 4 has three. Therefore:
- probability of a win = 6 / 9;
- probability of a loss = 3 / 9;
- net win after commission = $19;
- losing amount = $40.
Expected value per resolved bet is:
EV = (6/9 × $19) − (3/9 × $40)
EV = $12.67 − $13.33 = −$0.67
Here, EV is the long-run average profit or loss per resolved wager under the stated assumptions. The expected loss is about $0.67, equal to roughly 1.67% of the $40 amount laid.
Change the commission timing and the result changes. If the same $1 were charged on every decision, win or lose, the expected loss would be $1 per decision, or 2.5% of the $40 laid. Neither percentage should be applied to a casino whose rule uses a different base, timing, or rounding method.
How the same commission assumption prices each number
Using the same “5% of possible win, charged only on wins” assumption from the worked example, the standard-sized wagers compare as follows:
| Number laid against | Amount laid | True win | Commission on a win | Expected loss per decision | Loss as % of amount laid |
|---|---|---|---|---|---|
| 4 or 10 | $40 | $20 | $1 | about $0.67 | about 1.67% |
| 5 or 9 | $30 | $20 | $1 | $0.60 | 2.00% |
| 6 or 8 | $24 | $20 | $1 | about $0.55 | about 2.27% |
The percentages differ because the same $1 charge is spread across different amounts laid and different win probabilities. They are not universal published house edges. A casino that charges 5% of the lay amount, collects upfront, uses a minimum commission, or rounds to larger chip units will produce different effective costs.
Small wagers are especially sensitive to rounding. If a calculated commission is 50 cents but the table’s smallest usable charge is $1, the effective percentage doubles. Before comparing a lay bet with a Don’t Come wager plus odds, ask for the actual amount you must risk, the exact net win, and when the vig is collected.
Is the bet working on the come-out roll?
Do not assume. Some houses treat number wagers as off on a come-out roll unless the player calls them working; some have different procedures for lay bets; and electronic or stadium craps can display its own status. Ask before the dice are sent:
“Is my lay against 10 working on the come-out?”
The dealer can confirm the rule and mark or position the wager as required. The same caution applies if you want the bet taken down, moved, or reduced.
Taking down, moving, and repeating the bet
A standalone lay bet is generally not a contract bet. While betting is open, the player can normally ask to remove it, reduce it, increase it, or move it to another number. The dealer must recalculate both the true-odds win and any commission effect.
For example, moving $40 laid against 10 to 6 does not preserve a $20 win at the same risk. At true odds, winning $20 against 6 requires $24 laid. The dealer may return the excess, adjust the desired win, and handle the vig under house procedure.
After a winning decision, also confirm whether the bet remains up. Some layouts and electronic interfaces repeat number bets automatically; others settle and remove them unless the player instructs otherwise. “Same lay 10 for $40” is clearer than assuming the previous wager has silently continued.
A clean way to call the wager
State both the number and the win target or amount being laid:
- “Lay the 10 for $40.”
- “How much do I lay against 5 to win $40?”
- “Take down my lay 4.”
Then listen for the dealer’s repeat and look at where the chips are placed. Do not toss chips toward a number and rely on the dealer to infer whether you meant a place bet to lose, a lay bet, or odds behind a Don’t wager.
A lay bet can win frequently, especially against 4 or 10, but that frequency does not make it a guaranteed or even-money proposition. The larger losing amount and the commission are the price of taking the seven side of the contest.