How to play Edge Letters
Place each letter exactly once in every row and column, with blank squares between; edge letters show which letter you meet first from that side. Also known as ABC puzzle, Letters from the edge.
The rules
- Each row and each column contains every letter of the set exactly once.
- The other squares in each row and column are blank.
- A letter outside the grid is the first letter you meet when you look along that row or column from that side. Blank squares may come before it.
Playing Edge Letters on Puzzle Solvers
- Choose a grid and letter set and a difficulty, then press New Puzzle.
- Tap a square, then press a letter on the pad (or type it). ✕ marks a blank square; right-click also marks blank.
- Turn on ✎ notes to pencil in possible letters.
- Edge letters turn green when the first letter seen from that side is right. Hint explains the next deduction.
Using the Edge Letters solver
- Choose the grid and letter set and type the edge letters (or press Sample).
- Press Solve and step through: letters already placed, the only square left for a letter, and edge letters that fix the first letter in a line.
A worked example
In a 5×5 with A, B and C, each line has two blanks. If the left clue of row 1 is C, then C is in one of the first three squares, and neither A nor B can come before it.
If row 3 has B on the left and B on the right, B is the only letter in row 3 that could be both first and last — impossible unless the row has just one letter, so recheck: different letters at both ends fix the order of the line.
Strategies
- Next to the edge. With only a few blanks per line, the edge letter must sit in one of the first few squares from its side.
- Not first. A letter that is the first seen from the left can’t be in the last square, and no other letter can appear before it.
- Opposite edges. When both ends of a line have clues, the first and last letters are fixed — the remaining letters go between them.
- Once per line. When a line has a letter placed, cross that letter off the rest of the line — just like Sudoku.
- Count blanks. If a line already has all its blanks, every other square in it holds a letter.
Common mistakes
- Treating the edge letter as the letter in the first square — blanks may come first.
- Forgetting that every letter must appear in every line.
- Putting too many blanks in a line.
Where it comes from
Letter edge-clue puzzles are a classic of puzzle magazines and championships, often printed with the letters A, B and C. They train the same elimination skills as Sudoku with a twist of looking from the edge.
Frequently asked questions
Do blanks count as letters?
No — blanks are simply empty squares and are skipped when you look in from the edge.
Why do some puzzles have letters inside the grid?
A few given letters are added when the edge clues alone would allow more than one answer.
Is there always one answer?
Yes — every puzzle here is checked to have exactly one solution.
How do I solve one from a book?
Open the Edge Letters Solver, type the edge letters and press Solve.
Keep going
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- Edge Letters Solverstep by step, every move explained
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