Roll dice with standard notation, flip fair coins, and shuffle or draw playing cards. Every outcome comes from a cryptographic draw with equal odds on each face, and each tool explains the probabilities behind it.
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- Flip a CoinFlip a fair coin online — once, a hundred times, or as a best-of-three series.
- Dice RollerRoll any dice using standard notation — 2d6+3, 4d8, d20, or several dice types at once.
- D20 Dice RollerRoll a twenty-sided die with advantage and disadvantage built in — roll twice and keep the higher or lower, with the discarded die shown so the result is checkable.
- D100 Dice RollerRoll percentile dice — a single number from 1 to 100, the format used for percentage chances in tabletop games and random tables.
- D&D Dice RollerRoll ability scores as 4d6 drop lowest — six times, with the discarded die and the resulting modifier shown for each — or roll any attack, damage or healing expression in standard notation.
- Dice Probability SimulatorSimulate thousands of dice rolls and compare the result with the exact probabilities, which the tool calculates rather than estimates.
- Playing Card ShufflerShuffle a standard 52-card deck — optionally with jokers — using a Fisher–Yates shuffle driven by an unbiased integer source, so no ordering is favoured over another.
- Random Card DrawerDraw a number of cards at random from a standard deck, with no card drawn twice in the same hand.
Frequently asked questions
Are these dice and coins fair?
Yes. Every face has an equal chance on each roll or flip, drawn from your browser's cryptographic random source with unbiased sampling. Physical dice and coins are usually slightly biased by manufacturing and by how they are thrown.
Why do dice totals cluster in the middle?
Because sums of several dice are not uniform even though each die is. With 2d6 there are six ways to roll 7 but only one way to roll 2 or 12, so the middle totals appear far more often. Each individual die remains perfectly fair.
What dice notation is supported?
The standard NdS form with modifiers — 2d6+3, 4d8, d20 — including expressions that combine groups such as 3d8+2d4-1. Dice may have up to 1,000 sides, with up to 200 dice per group.
Does a run of heads change the next flip?
No. Each flip is independent, so the next one is always 50/50 no matter what came before. Expecting the balance to "correct itself" is the gambler's fallacy; the running tally shown is a record, not a prediction.
How are the playing cards shuffled?
With a Fisher–Yates shuffle over the full deck, so every possible ordering is equally likely and no card can appear twice. Drawing cards takes them from the top of a freshly shuffled deck, exactly as a physical draw would.
Can I use these for tabletop games online?
Yes — the dice roller accepts the notation most systems use and shows each die separately as well as the total, so results can be read out or pasted into a chat. Seeded mode is useful for play-by-post games where rolls need to be verifiable.
Do these tools work without animation?
Yes. Every animated tool has a still mode, and all of them honour your device's reduced-motion setting. The result is always present as text, so nothing depends on seeing the animation.
Dice, coins and cards with the maths explained
These tools simulate the physical randomisers people already understand — dice, coins, a deck of cards — and add the thing the physical versions cannot: an explanation of the probabilities, and a guarantee of fairness that real objects rarely meet.
Every draw on this page starts with crypto.getRandomValues, the cryptographically strong random source built into your browser. That is a CSPRNG seeded from operating-system entropy: unpredictable in practice, and the right choice when a result decides something that matters. It is deliberately not described as “true randomness”, which would require a physical entropy source such as atmospheric noise or radioactive decay. Tools that claim true randomness from a browser are overstating what the platform provides.
Fairer than the real thing
Physical dice are usually slightly biased. Pips are drilled out and filled, which shifts the centre of mass toward the face with fewest pips; cheap dice have rounded edges of uneven radius; coins are not symmetric and their behaviour depends on how they are thrown. None of these effects is large, but all of them are real. A generated draw has no geometry to be wrong about — every face has exactly equal probability by construction.
The distributions worth understanding
Each individual die here is uniform, but sums of dice are not, and this trips people up constantly. With 2d6 there is one way to roll 2 and six ways to roll 7, so 7 appears six times as often. Adding more dice concentrates results harder toward the middle. Understanding this is the difference between designing a game mechanic that works and one that feels wrong in play.
Coins raise a different misunderstanding: the belief that a run of heads makes tails due. It does not. Each flip is independent, and long-run balance comes from later flips diluting early imbalance, not from any correction.
Cards and shuffling
A deck shuffle uses Fisher–Yates across the full deck, so every ordering is equally likely and no card can appear twice. Drawing takes cards from the top of a freshly shuffled deck, exactly as a physical draw does — which means drawn cards are dependent events, unlike dice rolls.
Accessibility
Animation in these tools is decorative. Every result exists as text before any movement happens, is announced to screen readers, and can be shown with animation disabled — either through each tool’s still mode or automatically, if your device requests reduced motion.
Reading dice notation
The dice roller accepts the standard notation used by tabletop games. 2d6 means roll two six-sided dice and add them; 1d20+5 rolls one twenty-sided die and adds five to the total; 4d6 rolls four six-sided dice. The number before the d is how many dice, the number after it is how many faces each die has, and a trailing + or - applies a modifier to the total rather than to each die.
Adding dice together changes the shape of the results. A single d6 is flat: every face from 1 to 6 is equally likely. Two d6 are not — there is one way to make 2 and six ways to make 7, so totals cluster in the middle. This is why 2d6 and 1d12 feel so different in play despite covering a similar span.
Why fair sequences look unfair
Runs are a normal feature of independent draws, not evidence that a generator is broken. Each coin flip is decided on its own, with no memory of what came before, so a sequence of several heads in a row is expected to appear from time to time in a long enough run. The common intuition that a change is now “due” describes no property of the coin — the next flip remains an even chance regardless of what preceded it. The same reasoning applies to dice: a die that has not shown a six for a while is no more likely to show one on the next roll.
