Extreme · November 13

What makes Extreme its own level

Extreme is not a denser version of Expert: it is a break in the techniques required. Where Expert closes out with triples, quads and an X-Wing, Extreme almost always calls for at least one Wing (XY-Wing or XYZ-Wing) or a fish of size 3 or 4 (Swordfish, Jellyfish).

These techniques no longer live inside a single zone (row, column, box). They cross several rows and columns, or chain cells with two candidates. That crossing is what makes them hard: you have to hold several cells in mind at once and check that no case falls out of the pattern.

One last point to be upfront about: some Extreme puzzles may require techniques beyond the catalogue, or reasoned trial and error, where you assume a digit to see where it leads. That is not a flaw, it is the nature of the level.

Who this level is for

Extreme suits players who master every technique of the previous levels and want a real brain-teaser. These puzzles are rarely solved in one go: you move forward, get stuck, and go back over your notes.

If you are new to the Wings or the Swordfish, start with a few Expert puzzles first: the hardest technique the engine allows there tops out at the X-Wing, so you can get used to the fish patterns without chaining wings. Come back to Extreme once those patterns are second nature.

No duration and no success rate is quoted for this level: the gap between puzzles is too wide, and average numbers would say little that is useful.

The techniques you need

Everything before remains necessary, from the singles to triples, quads and the X-Wing. The Solvissima catalogue places four more techniques at this level.

The XY-Wing chains three bi-value cells in a Y shape: a pivot XY, a wing YZ, a wing XZ. Digit Z is eliminated from any cell that sees both wings. The XYZ-Wing works the same way with a three-candidate pivot, and also eliminates Z from cells that see the pivot.

The Swordfish extends the X-Wing to three rows and three columns, the Jellyfish to four. Each technique has its own page, with a demonstration on a real puzzle. Open one from the Learn menu, then switch to its practice grid.

Tips to move forward on an Extreme puzzle

Pencil in candidates from the start. On an Extreme puzzle, eliminations chain one after another, and none of them are visible without notes. One click on the board’s candidates button turns them on automatically.

Run through techniques in the engine’s order. Naked and Hidden Singles, pairs and triples come first; then look for an X-Wing; then an XY-Wing; then a Swordfish. Hunting for a Jellyfish first wastes time when a Hidden Pair would have done.

Keep track of what you tried. If you stall for ten minutes, write down the cell that feels tightest and the pattern you were looking for. Come back after a short break: fresh eyes almost always see a Hidden Pair or a Wing that you missed.

If nothing unlocks, ask for a hint on the board: Solvissima points at the cell and the technique that would move things forward, without revealing the solution.

How to play here

This page gives you today’s Extreme puzzle, renewed every day at midnight UTC. The board menu lets you load another puzzle of the same level, check at any point, ask for a hint, or read the engine’s explanation.

The Extreme level is not part of the daily challenge or the ranking: you play at your own pace, with no comparison to other players. Extreme puzzles can also be printed as PDFs to play offline.

Improving, or stepping back without shame

To improve, discover the techniques one by one on the Learn page, with their demonstrations. A pattern recognized in practice is much faster to spot in a real puzzle.

Going back to Expert after an Extreme puzzle that held out is nothing to be ashamed of: this level is meant to be demanding, and the most experienced players sometimes stall on it. Setting a puzzle aside and coming back later with fresh eyes is also a good method.

Frequently asked questions