Duel Originals
Slots come from providers and play the same everywhere, which is why everyone reviews them. Originals are built in-house — so nobody has bothered to write down the maths. That is what this section is.
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Dice, measured
The interface prints a 49.95% win chance at 2.0000×. Multiply them and you have the house edge — 0.10%, ten times smaller than the usual setup.
Plinko, counted
Sixteen rows is sixteen coin flips. We summed the whole binomial: about 99.2% RTP, and four drops in five land in a 0.2× bucket.
Castle Roulette
One zero pocket is worth 2.70% of every bet. There are exactly three ways to remove it and each fixes a different part of the table.
Rock Paper Scissors
Player against player, so there is no house edge to argue about — only whether the matchmaking and resolution are honest.
Video Poker
Two numbers on the paytable decide about 2.5% of your return, and almost nobody reads them before playing.
Blackjack
No house edge under correct play, so the margin is whatever you give away. Failing to split aces alone costs 38% of the bet.
Crash, and the cashout
The round history strip is the most misleading thing on the screen. Why no cashout system changes the expectation, and what the live bet list actually is.
Limbo
One input, one fair answer. A 10× target must win exactly one time in ten — anything less is the margin, and you can read it off the screen.
Keno
Hit probabilities for five and ten picks, and why picking more numbers does not improve your odds.
Mines, by the numbers
Every multiplier derived from first principles, with the fair-payout table so you can measure the margin yourself.
The mathematics of ruin
At $100M wagered a 3% edge leaves a 99% chance of a heavy loss. We reran Duel's whole table to check it — all fifteen cells hold.
You cannot verify a slot
Originals can be checked round by round. Slots cannot be checked at all — here is what actually stands behind a slot's RTP figure instead.
99% vs 99.9% RTP, simulated
Under one percent apart on paper. Over a hundred thousand bets it is the difference between one player in a thousand finishing ahead and one in three.
Zero edge, and why it needs a ceiling
A game taking nothing is easy to build and hard to survive. The variance problem behind it, and why the caps are the offer working rather than a catch.
Provably fair, verified
What the seed commitment actually proves, plus a tool that hashes a revealed seed in your browser so you can check a round.
The twelve Originals
The lobby badges every in-house title at 100%. Duel's own game artwork puts the same titles at 99.9%. Our measurements land on the artwork's side: Dice computes to exactly 99.90% from the two numbers it prints on screen, Plinko to about 99.2% once the whole payout table is summed.
So 100% is the rounded version and 99.9% is what the product actually states. That is not a gotcha — a 0.1% edge is an order of magnitude better than anything else on the market, and the pages below show the arithmetic rather than asking anyone to take it on trust.
| Game | Type | Badge |
|---|---|---|
| Dice | Adjustable win chance, 2× at 49.95% | 99.90% measured |
| Blackjack | Live table, no edge under perfect play | 100% RTP |
| Plinko | 16 rows, 17 buckets, 3 risk levels | ~99.2% measured |
| Crash | Rising multiplier, one cashout decision | 100% RTP |
| Mines | 5×5 grid, 3 mines by default | 100% RTP |
| Beef | In-house format, rules unpublished | 100% RTP |
| Keno | 40 numbers, pick 1–10, four risk levels | 100% RTP |
| Castle Roulette | Live wheel from Duel's own studio | 100% RTP |
| Video Poker | Draw poker, return set by paytable | 100% RTP |
| Groomer's Van | In-house format, rules unpublished | 100% RTP |
| Rock Paper Scissors | Player versus player, no house counterparty | 100% RTP |
| Limbo | Target multiplier, chance = 1 ÷ target | 100% RTP |
A 100% badge means the game is not built to take anything from you — which is only possible with limits on how much zero-edge action you can take, for reasons worth understanding. Two of these, Rock Paper Scissors and Castle Roulette, were roadmap items in Duel's own FAQ and have since shipped.
Why these are worth understanding
An in-house game publishes the pieces you need to check it: a server seed, a client seed you control, a nonce, and a hash committed before the round. That combination means the outcome can be verified after the fact rather than taken on trust — a guarantee a normal slot cannot offer you.
It also means the odds are computable. Where a slot's return is a figure the provider states and you accept, an Originals payout can be derived from the rules. If the game pays less than the derivation says it should, the difference is the house edge, and you can measure it to four decimal places without asking anyone.
What gets covered
Each game gets the same treatment: the rules, the probability behind every outcome, how a payout is calculated, what a zero-edge version would pay, and where the margin is taken. No strategy that claims to beat a fixed edge, because none exists — the honest version of strategy here is knowing what you are being charged.
Verify it yourself
Every Originals round can be checked against its seeds after the fact.
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