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Dice & Coin Roller

Roll any standard polyhedral die — d4, d6, d8, d10, d12, d20, or d100 — in batches of up to 20 and see every individual result plus the total, or flip a fair coin. Each roll is generated with the Web Crypto API (crypto.getRandomValues), a cryptographically secure random source, using rejection sampling: 32-bit draws that would introduce a modulo bias are discarded and redrawn, so every face lands with exactly the same probability. Your last 10 rolls and flips stay in an on-page history. The die list covers the classic tabletop set: d20 for D&D checks and saving throws, 2d6 for many board games, d100 (percentile) for roll-under systems such as Call of Cthulhu, plus a coin for quick binary decisions. Because it runs entirely in your browser with no account or server round-trip, it's the fastest replacement when the physical dice have gone missing — though for remote games where opponents need to verify a roll, a shared dice bot in your group chat is the better fit.

Dice

Coin

How to use

  1. Pick a die (d4, d6, d8, d10, d12, d20, or d100) and how many to roll (1–20).
  2. Hit Roll — each die's result appears as its own tile, with the sum shown underneath.
  3. Use Flip in the Coin section for a fair heads-or-tails call.
  4. Your last 10 rolls and flips are listed under History; Clear empties the list.

Frequently asked questions

How random are the rolls?
Each roll draws 32-bit values from crypto.getRandomValues — the same cryptographically secure generator browsers use for keys and tokens — and rejection sampling discards any draw that would skew the distribution. Every face therefore has exactly equal probability, avoiding the modulo bias of the naive `random() % sides` approach.
Can I roll more than 20 dice at once?
The count is capped at 20 so the result tiles stay readable. If you need a bigger pool (say 30d6), roll twice and add the totals — the rolls are independent, so the combined sum is statistically identical to one big roll.
What is a d100 used for?
The d100 (percentile die) drives roll-under systems: if your skill is 65%, you succeed on a roll of 65 or lower. At a physical table it's usually thrown as two d10s read as tens and units; here you get the 1–100 result in a single roll.
Is the roll history saved anywhere?
No — it lives in memory for the current page view only and keeps just the last 10 results. Reloading or leaving the page clears it, and nothing is ever sent to a server.
Can someone else verify my roll was fair?
No. Like physical dice rolled in private, the result can't be proven to a third party after the fact — there's no seed or audit log. The rolls themselves are unbiased, but for remote play where trust matters, use a dice bot that rolls in a shared channel so everyone sees the same result.

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