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Luckverse

How fairness works

Every result on LUCKVERSE is drawn first, with care, and only then animated. Here is exactly how.

The random source

All tools use crypto.getRandomValues(), the cryptographically secure random number generator built into every modern browser. It is the same source browsers use for encryption keys, and it cannot be predicted from earlier results.

Whole numbers without bias

A common shortcut, taking a random number and using the remainder after dividing by the range, slightly favours small values. LUCKVERSE uses rejection sampling instead: values that would cause that bias are thrown away and drawn again. Every number in a range is exactly as likely as every other.

Weights are exact

On a weighted wheel, an entry with weight 3 is drawn with probability 3 divided by the total weight, using one unbiased whole-number draw over the total. The size of each slice is computed from the same weights, so the picture shows the true odds.

The animation follows the draw

The winner is chosen before the wheel moves. The wheel then turns several times and slows down to land inside the winner’s slice, away from its edges. When it stops, the slice under the pointer is checked against the drawn winner. Our automated tests repeat this twenty thousand times on every build.

Fair ladders

A ladder lottery drawn at random is usually not fair: with a handful of rungs, people tend to end near where they started. LUCKVERSE first draws a uniformly random outcome, then builds a ladder that leads to exactly that outcome. Every way of matching people to results is equally likely, and every ladder is checked so that each line reaches a different result.

Provable draws

For giveaways, the Name Picker can run a draw anyone can check afterwards:

  1. A secret 256-bit seed is created. Its fingerprint, SHA-256 of the seed together with a hash of the exact list, is shown for you to publish.
  2. Optionally, your audience supplies a public salt after the fingerprint is posted.
  3. The winners are computed from the seed and salt with a deterministic SHA-256 stream and the same unbiased sampling.
  4. You reveal the seed. Anyone can open the Verify page, recompute the fingerprint and the winners, and confirm nothing changed.

What we do not do

LUCKVERSE has no betting, no money and no prizes of its own. Results are not stored on a server: your lists and history stay in your browser.