Deal or No Deal glossary

Short definitions of every term you meet in Deal or No Deal on dond.win: Banker, buy-in, case, ladder, mean, offer factor, opening fee, commitment, server seed, client seed, settle, house edge.

Game terms

• Banker. The function that offers you money for your sealed case after every open. On dond.win it is a published formula, not a person.
• Buy-in. Your stake for one round. All prizes and offers are multiples of it.
• Case. One of the 25 containers on the board. Each hides a multiplier. Your case is the one you picked first and it stays sealed.
• Deal. Accepting the Banker’s current offer. The round ends and the offer is paid.
• No deal. Refusing the offer. On dond.win you refuse by opening another case.
• Ladder. The fixed list of 25 multipliers, from 0.1× to 10×, that is shuffled into the cases every round.
• Multiplier. A prize expressed as a multiple of the buy-in. A 2.5× case in a 10-dollar round pays 25 dollars.
• Open. Revealing the prize in a case that is not yours. The prize is removed from the board.
• Opening fee. The charge for opens past the free ones, as a percentage of the buy-in.
• Offer factor (k). The discount the Banker applies to the fair value of your case. Rises from a base on the first open to a cap on the 23rd.
• Mean of remaining. The average of the prizes still on the board. The fair value of your case at that moment.
• Settle. The end of a round, either by dealing or by opening the 24th case. The payout is credited at settlement.
• Expected value (EV). The long-run average result of a decision. For a case, the mean of the remaining prizes.
• House edge. The share of total stakes the game keeps over the long run. Comes from the opening fees and the offer factor.
• Variance. How widely results swing around the average. High in this game because of the 5× and 10× cases.

Fairness terms

• Provably fair. A scheme where the operator commits to the random outcome before you act and reveals the inputs afterwards so you can verify it.
• Server seed. The secret random value the server draws for a round.
• Commitment. The SHA-256 hash of the server seed, shown before you pick a case.
• Client seed. Your own input to the shuffle. Random by default, editable before a round.
• HMAC-SHA256. The keyed hash that turns the two seeds into the random bytes for the shuffle.
• Fisher-Yates. The standard algorithm for producing a uniformly random permutation; used to place the ladder into the cases.
• Verify. Recomputing the commitment and the layout from the revealed seeds. Done on the verification page.

Money terms

• USDT / USDC. Dollar stablecoins used for real play. Treated as equal.
• Deposit address. The personal address you send tokens to; credited after chain confirmation.
• Confirmation. A block that includes your transaction. Deposits are credited after a chain-specific number of confirmations.
• Network fee. The flat charge for sending a withdrawal on a given chain.
• Demo / play money. A balance that is not real, used to learn the game without risk.