How to Make a Crossword Puzzle That Actually Interlocks

A crossword is supposed to interlock: every word crosses at least one other word through a shared letter. Get that wrong and you don't have a crossword, you have a list of words sitting in separate boxes. This is the single hardest printable to build by hand, and the easiest one to get visibly wrong.

Here is what actually makes a crossword interlock properly, and how to build one without redoing it three times.

Why crosswords break when you build them by hand

Placing the first word is easy. Placing the second word so it crosses the first through a real shared letter is where it gets hard, and every word after that has to be checked against every word already placed, not just the one it's meant to cross. Miss a collision and two words silently overwrite each other's letters.

What a working crossword needs

• Every word threaded through a shared letter with at least one other word.
• No two words colliding (overlapping without sharing the same letter at that cell).
• No accidental extra words forming in the grid that were not intended.
• A numbered grid, with matching Across and Down clues.
• A real answer key.

1. Write your word list and a clue for each word.
2. Place the longest word first, then thread each remaining word through a shared letter.
3. Check every new placement against every word already in the grid, not just its intended crossing.
4. Number the grid automatically once placement is confirmed.
5. Generate the Across and Down clue lists and the answer key.
6. Personalise in Canva and export.

If a word in your list genuinely will not fit (no shared letter with anything already placed), the honest fix is to report it as unplaceable and swap it for another word, not to force it in loose and unconnected. A crossword with a floating, non-interlocking word is worse than one with fewer, well-connected words.

Common questions