Daily Triplets

Daily Triplets is based on a classic psychology experiment, Wason's 2-4-6 task, in which people are shown a sequence that fits a rule and have to discover the rule by proposing more examples. Here the examples are three digits from 0 to 9, and each day has a new numbered secret rule, the same for every player. The first puzzle went up on 1 June 2026.

The board starts with one triplet that fits today's rule, such as 5 3 8. You type any three digits and press Test: the triplet joins a list marked with a tick if the rule accepts it or a cross if it does not. There is no limit on tests, and the list can be filtered to fits or misses and sorted up or down to spot the pattern.

When you think you have it, press I know the rule and write it as an equation. You can use a, b and c for the three digits, x for the triplet read as a three-digit number, sum for their total, and abs, max and min. The game checks your answer against all 1,000 possible triplets, so any equivalent way of writing it counts, and a wrong answer shows a triplet where your rule and the real one disagree. You have three attempts.

Rules range from simple orderings (a < b < c) to sums, products and comparisons such as max(a, b) < c. The trap the original experiment is known for is only testing examples you expect to fit: testing triplets you expect to fail is what shows the rule's edges. A calendar opens earlier days, a stats panel keeps your streak and how many attempts you needed, and a result can be copied to share. There are no ads and no sign-up.