How to play Twill

The rules

• Every square takes one of two threads: light or dark. Some squares are woven for you at the start.
• Every row and every column has as many light squares as dark ones (three of each on a 6x6 swatch, four on an 8x8).
• Never three of the same thread side by side, across or down.
• A tie (=) between two squares means they are the same thread. A cross (x) means they are different.
• On Sundays (twill day) no two rows may be woven exactly alike, and no two columns either.

Playing on a phone or a computer

• Tap a square once for light, twice for dark and a third time to clear it. The squares woven for you (with a small knot in the middle) cannot be changed.
• Drag from a woven square along its row or column to copy its thread along the line (from an empty square, the drag weaves light).
• Squares that break a rule are outlined in red. You can switch that off, and you can switch on a count of light and dark threads beside every row and column.
• Undo steps back one move at a time. On a keyboard, use the arrow keys to move, L or 1 for light, D or 2 for dark and Backspace to clear.

The week

Monday and Tuesday are Easy 6x6 swatches and Wednesday and Thursday are Medium 6x6. Friday and Saturday are Hard 8x8 swatches, and Sunday is twill day: 8x8 with the no-two-alike rule. The level comes from the ideas a swatch needs, as worked out by our solver (see below), not just its size.

Scoring

You start on 1,000 points and lose a point for every second on the clock (three quarters of a point on the 8x8 Hard and twill days) and 50 for each hint. Any finished swatch scores at least 100, and giving up scores 0 and shows you the solution. The clock starts when you press Start and runs on our server, so a refresh does not reset it.

Techniques, from easy to hard

1. Pairs and gaps

Two dark threads side by side? The squares at either end must be light. A single gap between two dark threads must be light too. The same goes for light. A tie or a cross next to a woven square tells you its partner straight away.

2. Count to half

Once a row or column has half its squares light, everything else in it is dark, and the other way round. Easy swatches need nothing more than this and pairs.

3. Finish the line in your head

Take a row or column with a few gaps and try every way to fill it that keeps half of each thread, avoids three in a row and obeys its own ties and crosses. If every way agrees on a square, that square is settled. Medium swatches are built around this idea.

4. No twins (Sundays)

On twill day, if a row is nearly finished and one way to finish it would copy a row that is already complete, that way is ruled out.

5. What if?

Harder swatches sometimes need a short test: imagine a square light, follow the pairs, gaps, ties and counts, and if a rule breaks within a few moves, the square is dark. It is a quick check, not a guess: our solver never needs more than two per swatch, each no more than five moves long.

Hints

Stuck? A hint lights up the next square and the row or column it comes from, explains the deduction in plain words and offers to weave it for you. If a square you have woven is already wrong, the hint points that out first.

Endless mode

Want more than one a day? The loop button at the top opens endless mode: hundreds more swatches at Easy, Medium, Hard and Twill, played at your own pace with unlimited hints. Your progress, best and average times stay on your device. The last seven daily swatches can also be replayed from the calendar.

Every finished swatch, with its solution, is in the Twill answers archive. For the other daily games, see the dailies page.

Frequently asked questions

Does Twill ever need guessing?

No. Every swatch has exactly one solution, proved by a computer, and our solver reaches it using only the kinds of ideas described above.

What is twill day?

Sunday's swatch is 8x8 and, as well as the usual rules, no two rows and no two columns may be woven the same.

How is Twill scored?

You start on 1,000 points and lose up to a point a second and 50 per hint. Any finish scores at least 100; giving up scores 0.

Is Twill free?

Yes. Twill is free to play in any web browser, on a phone or a computer. There is nothing to install and no account to make.

What time does the new Twill swatch come out?

At midnight UK time (GMT in winter, BST in summer). Everyone gets the same swatch on the same day. If you have the old puzzle open at midnight, you have 30 minutes to finish it and still have it count.

Can I play more than one Twill a day?

Yes. Endless mode has hundreds of extra swatches at four levels, and the last seven daily swatches can be replayed from the calendar. Neither affects your daily score or streak.

Where can I see yesterday's Twill solution?

The Twill answers archive shows every finished swatch with its solution. Today's swatch never appears there until the day is over.