Fill-In

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3. Fill-In

No clues and no definitions: just an empty criss-cross grid and the list of words that go into it. Every word has exactly one place in the finished grid, and finding it is a matter of lengths and crossing letters.

How Fill-In works

Tap a word in the list and then a place in the grid, or tap a place first and then the word. A word fits where the length is right and the letters it crosses agree with the words already placed. Tap a placed word in the list to take it out again.

There is exactly one way to place all the words. The generator checks every possible filling, and where two fillings would work it prints a few letters into the grid at the start until only one remains. Easy has six to eight words of three to six letters, Medium ten to twelve words of up to seven letters and Hard fourteen to seventeen words of up to nine letters.

The list groups the words by length, which is the first thing to look at. Undo takes back the last placement, and Hint puts one word where it belongs.

Ways to fit the grid

• Start with a length that appears once. If only one word has seven letters, the grid has only one seven-letter place, and that word goes there. Many puzzles have two or three such words.
• Then follow the crossings. Each placed word fixes letters in the places it crosses. A place with two known letters usually leaves only one word of the right length.
• Pick the busiest place. Among places of the same length, the one with the most crossings is where a wrong word shows itself fastest.
• Use the printed letters. Letters in the grid at the start are there to rule out a second solution, which makes them strong clues.
• Do not be afraid to undo. A word that fits is not always a word that belongs. If a later word has nowhere to go, take back the last few placements.

Questions about Fill-In