How Rarebit works

In short

Every number from 0 to 999,999 has exactly the same chance of being rolled. Your roll is saved before you see it, so reloading or opening another tab can’t change it. Rare patterns earn more points, and all one million numbers have been scored, so every roll gets an exact rank. The details are below.

The random draw

Your daily number is drawn on DailyPlay’s server with crypto.getRandomValues, the platform’s cryptographic random source. It produces a 32-bit value; values at or above 4,294,000,000 (the largest multiple of 1,000,000 that fits) are thrown away and drawn again, and the rest are reduced to 0–999,999. That rejection step removes modulo bias, so every number has exactly the same chance.

There is one daily roll per account or device per New York calendar day. The server saves the roll before it answers, so retries, reloads and second tabs return the same number. Practice rolls use the same method in your browser and are never saved on the server.

Scoring

A badge’s odds p is the number of numbers that earn it divided by 1,000,000. Its points are round(10 × log2(1/p)), so a badge half as common is worth 10 more points. A number’s score adds, for each of the six families, the highest-point badge it earns in that family; every badge is still shown. Rank is 1 plus the count of numbers with a strictly higher score, so ties share the better rank. Top P% is rank ÷ 10,000 and is never shown as 0%. For numbers in the lower half (Top P% above 50), Rarebit shows Bottom B% instead: the count of numbers scoring the same or lower, ÷ 10,000. The score, rank and tier are the same either way.

How the numbers were produced

A script scores every number from 0 to 999,999 with the same scoring module the game uses in your browser and on the server. It counts how many numbers earn each badge, builds the full score histogram and lists the top and bottom 100 (by score, then by number). The scoring version is a hash of the scoring module, and an automated test re-runs the enumeration and checks the hash and totals, so the published counts always match the rules.

Changelog

• v1, 2026-11-20: launch with 53 badges in six families.

Current scoring version: 5c5e7404cc3f. The version is a hash of the scoring module, so any change to the rules changes it.

What is stored, and for how long

• Daily roll records: the number, the date and an account or guest id.
• Guest records are kept for 400 days unless claimed into an account. Account records are kept until the account is deleted.
• Practice rolls and your badge collection stay only on your device.
• A salted hash of your IP address is kept for 24 hours to limit guest rolls. The raw IP is not stored.

If this device and your account both rolled on the same day, the account’s earlier roll stays and this device’s roll is kept as unranked. See the privacy policy for the rest of DailyPlay.

Today’s best roll is the best ranked roll today. Guest rolls are limited to 20 ranked rolls per network each day (shared Wi-Fi counts as one). Rolls over that limit are kept and still count for the player, but they are unranked: not eligible for today’s best. Signed-in rolls are always ranked.