How Online Dice Get Rigged (And How To Spot It)

A physical die can be loaded, shaved, or palmed. A virtual die can be tampered with in four broadly different places, and knowing which is which tells you what evidence to ask for.

The first and by far the most common is the overlay. A browser extension or an OBS filter simply draws a different colour on top of the real result after it lands. The site is honest, the maths is honest, and the picture your viewers see is a lie. Nothing the roller does to its own randomness can prevent this, which is why a viewer needs a channel to the result that does not pass through the streamer's screen.

The second is a seeded generator. Many sites use a pseudo-random function seeded with something predictable, like the current second or an incrementing counter. Anyone who works out the seed can compute the next thousand outcomes. This is not a hypothetical; it has broken real lotteries and real online casinos.

The third is a modulo bias. A developer grabs 32 random bits and takes the remainder modulo six. Because 2^32 is not divisible by six, two of the six faces come up very slightly more often. The effect is tiny — a fraction of a percent — but it is real, permanent, and completely avoidable with rejection sampling, which simply throws away the handful of values that would skew the split and draws again.

The fourth is a server replay. The result is generated on a server, which means the operator can decide it, log it, resell it, or change it before it reaches you. A roll that never leaves your device cannot be reordered by anybody.

Strawberry Dice is built to close three of the four outright: results come from the browser's cryptographic generator, with rejection sampling, entirely on your device, with no server in the loop. For the fourth — the overlay — we give you the session code. A viewer types your code into the verify page and sees the roll history straight from the source, updating live, rather than trusting a rectangle of pixels on a stream.

So what should you ask of any dice site? Where does the entropy come from. Is there a seed and who knows it. Is there a bias in the reduction step. And can a third party read the result without going through my screen. A site that cannot answer those four questions is asking for faith, not offering proof.