Patch
Also known as Map colouring and Four colour map
Colour a map of irregular patches with coral, yellow, green and blue. Patches sharing an edge must have different colours, and each colour must fill exactly its displayed quota. A few patches start coloured and stay fixed. Every board has one solution that can be reached by deduction; trying a colour, changing it and undoing are all free of mistake penalties.
How it works
- Colour every patch.
- Touching patches can't have the same colour.
- Use each colour exactly the number of times shown.
Good if you want…
- Visual deduction with every clue visible from the start
- Combining local clues with counts across the whole board
- Working through an idea without a mistake limit
How to solve Patch
Start beside the fixed patches
A running stitch marks a patch whose colour is given. These are your starting clues, and they cannot be changed. Look at the patches sharing edges with them: each neighbour loses that fixed colour as an option. If a patch touches coral, yellow and blue, green is the only colour left. Fill it, then check its neighbours for the next forced choice.
Follow the actual borders rather than the positions of the colour symbols. A long patch may touch several others along different sides. Meeting at a corner does not make two patches neighbours, and a patch's area has no effect on its count: a large patch uses one place in its colour's quota, just like a small one.
Read the counts as clues
The palette shows how many patches have each colour beside the total that colour needs. Once blue reads 3/3, every other open patch must use another colour. That can settle a patch with only two options even when none of its neighbours has changed. Keep checking completed colours after each placement, because the clue applies everywhere on the board.
The reverse is useful too. Suppose coral needs two more patches and only two open patches can still take coral. Both must be coral, provided they do not touch. You are counting eligible patches, rather than picking the two nearest the existing coral. The quotas are part of the puzzle, and neighbouring colours alone will not settle every board.
Look at neighbouring options together
If two touching patches can each be only yellow or green, they must use one of each. A third patch touching both cannot use either colour, even before you know which of the pair is yellow. On harder boards, also check whether enough patches can take a colour without touching each other: three possible places do not provide three usable places if they all meet.
Use Undo to keep an idea clear
A red shared border marks equal colours on touching patches. A count above its quota marks another contradiction. Neither ends the round, so you can change a colour or undo a trial. Clear empties the patches you coloured while keeping the givens, and a single Undo brings those entries back. A hint fixes a wrong patch first, or fills the next useful patch if your entries are correct.
Common mistakes
- Counting a large patch more than once. Quotas count patches, not area.
- Treating a corner contact as a shared edge.
- Forgetting that a colour already at its quota is unavailable everywhere else.
- Filling all the quotas while leaving equal colours on touching patches. Both rules must hold at the same time.
Patch questions
How do the difficulties differ?
Easy has 8–10 patches and starts with neighbouring colours and completed quotas. Medium has 10–13 patches and a longer sequence of deductions. Hard has 13–16 patches and asks you to weigh where a colour has room. Expert has 15–18 patches and may need a short assumption followed to a contradiction. Every tier uses the same four colours.
Can I lose a round?
No. Patch shows clashes and counts above a quota without counting mistakes. You win when every patch is coloured, every shared edge separates different colours, and all four counts are exact. Fixed patches keep their given colours.
How do I change or clear a colour?
Choose a colour and tap a patch to fill or recolour it. Tapping a patch already in the chosen colour clears it. On a computer, 1–4 choose a colour, arrow keys move between patches, Enter fills and Backspace clears. A right-click clears a patch too; on iPhone, hold a coloured patch to clear it.
Patch in Winters Puzzles
Patch is one of 40 puzzles in Winters Puzzles, so it sits alongside Logic Grid, Pippin, Code Breaker and everything else in the app rather than being a download of its own. It counts towards your stats and streak like any other puzzle. It is not one of the puzzle types included in Pip’s dailies.
Play Patch.
Free on iPhone and iPad, with 39 other puzzles alongside it. Or play it in your browser — no download, nothing to sign up for.
