How to play
Rule
A hidden rule, six tests to find it. The fewer you spend, the better.
- A rule is hidden. Two triples that obey it are on the board to start you off.
- Test up to six triples of your own. Each comes back yes or no, and every test you leave unspent counts in your favour.
- Name the rule from the five candidates under the tests, then lock it in.
How it is scored
Naming the rule wins the day, and the grade is how few tests it took to get there. One or two is about as lean as a solve gets; using the whole bench of six still counts as solved, just not as sharp. The reveal also counts how many of your tests came back no, because a no is the only answer that rules anything out. Confirming your theory six times over is the losing line, and most people play it.
Six tests are a budget, not a checklist. Nothing makes you spend them, and the same rule named in two beats the same rule named in six.
How to get better at it
The whole game turns on one habit: test a triple you expect to be REJECTED. A test that confirms your idea teaches you almost nothing, because most wrong rules also accept the examples you were shown.
Say you think it is ascending. Testing 8, 10, 12 tells you very little. Testing 12, 10, 8 tells you whether order matters at all, and testing 2, 4, 100 tells you whether the gaps matter. Either can surprise you; the confirming test cannot.
Read the candidate rules before spending tests. They are all consistent with the examples, so the examples cannot separate them, and the differences between them tell you exactly which triples are worth trying.
If two candidates would both survive everything you have tested, you have not finished, and one more test is cheaper than a wrong answer. But the moment only one is left standing, stop: the tests you never had to spend are what separate a sharp solve from a lucky one.
When it resets
New puzzle at your local midnight.