Solitaire Battleships Puzzle

What is Solitaire Battleships?

Solitaire Battleships is a one-player logic puzzle based on the classic pen-and-paper game. Instead of guessing against an opponent, you are given a single grid with a whole fleet of ships hidden inside it, and your job is to work out exactly where every ship sits. The clues are the numbers printed along the edges: each number tells you how many ship segments lie in that row or column. A short list of revealed cells gives you a foothold to begin. Because the puzzle has one tidy solution, it rewards careful, step-by-step deduction rather than luck — making it a satisfying companion to Sudoku and Nonograms.

This generator builds a fresh puzzle every time. It first lays out a complete, valid fleet, then counts the segments in each row and column to produce the clues, so the puzzle and its answer key are always perfectly consistent.

The rules of the fleet

A few simple rules make the puzzle solvable by pure reasoning. First, the fleet is fixed and shown in the legend — for example one four-cell battleship, a couple of three-cell cruisers, some two-cell destroyers and several single submarines. Every ship must appear exactly once in the quantity shown. Second, ships are straight lines of cells, placed either horizontally or vertically; they are never bent or diagonal. Third, and most importantly, no two ships may touch each other, not even at a corner. Every ship is therefore surrounded by water on all sides, which is the key fact that lets you rule cells in and out. Finally, the row and column numbers must match the finished grid exactly: if a row says three, precisely three of its cells are ship.

How to solve it

Start with the extremes. A row or column whose number equals the grid width must be completely full, and one marked zero must be entirely water — shade those in straight away. Use the no-touching rule aggressively: as soon as you know a cell is part of a ship, every diagonally adjacent cell must be water, which often forces neighbouring rows and columns. Cross-reference the counts: if a column needs only one more segment and only one cell remains that is not already ruled out, that cell must be a ship. Keep an eye on the fleet legend too — once you have found the longest ship, you can stop looking for another of that size, which narrows the remaining possibilities. Mark water cells as confidently as ship cells; knowing where ships cannot go is just as powerful.

Choosing a grid size

Smaller grids carry a lighter fleet and make a gentle introduction for newcomers and younger solvers, while larger grids pack in more ships and demand more bookkeeping. Pick a size to match the solver and the time available: a small grid is a quick coffee-break puzzle, and a larger one is a proper sit-down challenge. Each size comes with a fleet scaled to fit, shown in the legend on the puzzle page so you always know exactly what you are hunting for.

Printing and classroom use

Every sheet prints on A4 or US Letter through the same branded template, with an optional Name and Date row for classroom sets and an optional answer key on a second page for quick marking. Because each generation is unique, you can hand a different puzzle to every pupil or print a stack for a puzzle club. Battleships is a friendly way to build the same skills Sudoku and logic grids develop — careful elimination, constraint-checking and patient reasoning — without any arithmetic, so it suits a wide range of ages.