Find the Q Among the Os — The Hard One

A Q is an O with a small tail. That is the entire difficulty of this puzzle, and it is enough.

Search of this kind is governed by how many features separate the target from its neighbours. A single distinguishing feature that is large and obvious — a different colour, a much bigger size — lets the target appear immediately, however many distractors are present. A single distinguishing feature that is small forces the visual system to check items more or less one at a time, and the time taken grows with the number of items on screen.

That is why this puzzle scales its difficulty in three ways at once.

What changes at hard difficulty

The grid gets bigger, which increases the number of checks.

The character pair gets closer. An 8 among 3s is visibly different in outline. A Q among Os differs by one small stroke in one position, and if the tail happens to sit where your eye is not, it may as well not be there.

The spacing gets slightly irregular. A small amount of random jitter is applied to each character’s position, which breaks the tidy lattice your eye uses to keep its place. It sounds trivial. It is not.

Doing it properly

Scan rows, not randomly. Use the row numbers down the side to keep track, and finish a row before moving on — the jitter is specifically designed to make you lose your place.

If you would like it harder still, try scanning columns instead. Most people find vertical scanning noticeably slower, which is itself interesting.

The reveal gives the exact square.