Deal or No Deal odds and expected value
The numbers behind Deal or No Deal on dond.win: the 25-prize ladder, a 4% chance of the 10× case, a 40% chance your case beats the buy-in, a mean case value of 1.46×, and where the house edge comes from.
The ladder
Every round uses the same 25 multipliers, shuffled uniformly at random:
| Below 1× (15 cases) | 1× and above (10 cases) |
|---|---|
| 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.8, 0.9 | 1, 1.1, 1.25, 1.5, 1.75, 2, 2.5, 3.5, 5, 10 |
There is no zero case. The smallest prize is 0.1× your buy-in; the largest is 10×.
Odds at the start
- Chance your case holds the 10×: 1 in 25, or 4%.
- Chance your case holds at least 2×: 5 in 25, or 20%.
- Chance your case holds at least 1× (you do not lose on the case itself): 10 in 25, or 40%.
- Median case: 0.7×. Half of all cases are worth 0.7× or less.
- Mean case: the 25 multipliers add up to 36.5, so the average case is 1.46× your buy-in.
A mean of 1.46× with only a 40% chance of beating 1× tells you the ladder is skewed: a few big prizes pull the average up, most cases are small. That shape is what makes the Banker’s offers tempting.
Odds change as you open
Your case is one of the remaining ones, so its distribution is always the set of prizes still on the board, each equally likely. With 10 cases left and the 10× still in play, your chance of holding it is 10%. With 2 left, it is 50%. The board always shows you exactly which prizes remain, so you can read your odds at a glance.
Where the house edge comes from
The prize ladder itself is generous: the average case pays 1.46× the buy-in. The house edge is built from two published sources instead:
- Opening fees. Opens past the free ones cost a percentage of your buy-in, and the rate steps up in the late game. The more you open, the more you pay.
- The offer discount. The Banker pays k times the fair value of your case, and k is below 1 at every point in the round.
How much of that edge you actually pay depends on how you play. A player who deals late pays more fees and gets a smaller discount; a player who deals early pays almost no fees but accepts a larger discount. The fee tiers and the discount parameters are shown in the game and published at /api/rules.
Variance
Because of the 10× and 5× cases, Deal or No Deal has high variance for a game with a modest edge. Big wins are real but rare; most rounds end in a deal somewhere between 0.5× and 2× of the buy-in. Size your buy-ins accordingly.
Frequently asked questions
What are the odds of winning 10× in Deal or No Deal?
At the start, 4%: one case in 25 holds the 10× multiplier. The chance rises as small prizes are opened and the 10× stays on the board, and drops to zero the moment someone opens it.
What is the expected value of a case?
The 25 multipliers sum to 36.5, so a random case is worth 1.46× the buy-in on average before any fees or offers.
What is the RTP or house edge of Deal or No Deal on dond.win?
The edge comes from the opening fees and the Banker’s discount, not from the prize ladder, and how much of it you pay depends on when you deal. The fee tiers and the discount parameters are shown in the game and published at /api/rules.
Is there a 0× or empty case?
No. Every case pays at least 0.1× the buy-in.