Ships in Battleships Puzzle cannot touch diagonally — distinct ships must stay separated by at least one water cell on every side, including at the corners. The rule applies to every ship pair on the board, so a length-3 cruiser, a length-2 destroyer, and a length-1 submarine cannot share even a single corner-touching cell. This corner rule is what separates Battleships Puzzle from the two-player guessing game: every placement is fully visible on one logic grid, so the constraint becomes a tight packing problem rather than a hunt. Conceptis documents the same prohibition in its Battleships ruleset, calling out that surrounding cells around each ship must remain water. On Lizely's fixed five-by-five fixture the rule combines with three other contracts — straight ships only, exact fleet sizes, and five row plus five column totals — to guide the placement of the disclosed six-cell fleet in six ship actions. Understanding why the corner spacing is enforced, and exactly which cell pairs trigger a rejection, is the fastest way to plan clean placements and reach the 940-point best score.
Why the Corner Spacing Rule Exists
The diagonal separation rule is what turns Battleships from a guessing game into a one-person logic puzzle. Conceptis describes the rule in its Battleships rules reference: ships cannot touch each other even diagonally, so every cell that touches a ship by edge or corner must stay empty. Without that constraint, a 5x5 grid with six ship cells would admit many overlapping fleets; with it, the disclosed arrangement satisfies every clue at once.
The Battleships Puzzle engine uses the rule as a hard validator. After each Space press it recomputes connected components of occupied cells, then checks the diagonal neighbors of every component. If a diagonal neighbor belongs to a different component, the placement is rejected as a contradiction. A placement that lets two ships kiss at a corner will not be accepted, even if every other constraint looks satisfied — the surrounding ring of water is part of the solution, not an optional decoration.
The corner rule also drives scoring. Because each ship action risks triggering a diagonal conflict, an experienced player places only the six cells that survive all four constraints: line shape, fleet size, clue totals, and water spacing. Six clean actions, no backtracking, score 940.
How the Fleet, Row, and Column Clues Interact
Beyond the no-diagonal rule, the puzzle asks you to fit a specific fleet onto a 5x5 grid whose line clues are fixed. The fleet is exactly six cells: one cruiser of length 3, one destroyer of length 2, and one submarine of length 1. The row clues from top to bottom are 3, 0, 1, 1, and 1. The column clues from left to right are 1, 2, 1, 0, and 2.
The clues and the fleet must agree on the total occupied count. Summing the row clues gives 3 + 0 + 1 + 1 + 1 = 6, and summing the column clues gives 1 + 2 + 1 + 0 + 2 = 6. Both equal the size of the disclosed fleet, which is a useful sanity check whenever the grid seems ambiguous. The single row with clue 0 means that row must be entirely water; the single column with clue 0 must also be entirely water. A zero clue line is therefore a strong anchor for the diagonal rule, because it guarantees no ship sits adjacent to its water corridor.
| Line | Clue | What it means for placement |
|---|---|---|
| Row 1 (top) | 3 | Exactly three ship segments occupy this row. |
| Row 2 | 0 | All five cells in this row must be water; this row anchors no-touch. |
| Row 3 | 1 | Exactly one ship segment occupies this row. |
| Row 4 | 1 | Exactly one ship segment occupies this row. |
| Row 5 (bottom) | 1 | Exactly one ship segment occupies this row. |
| Column 1 (left) | 1 | Exactly one ship segment occupies this column. |
| Column 2 | 2 | Exactly two ship segments occupy this column. |
| Column 3 | 1 | Exactly one ship segment occupies this column. |
| Column 4 | 0 | All five cells in this column must be water; no ship segment may touch it even diagonally. |
| Column 5 (right) | 2 | Exactly two ship segments occupy this column. |
Because two lines must be all water, the puzzle leaves four rows and four columns that can host ships. The combined capacity of those rows is 3 + 1 + 1 + 1 = 6, and the combined capacity of the four non-zero column clues is 1 + 2 + 1 + 2 = 6, matching the fleet exactly. Once the water row and water column are mentally subtracted, the placement grid is small enough that the no-diagonal rule alone forces the rest.
How to Place Ships Without Diagonal Contact
This step-by-step walks through the disclosed six-cell solution, applying the no-touch rule at every stage.
- Open Battleships Puzzle and read the five row clues and five column clues printed on the grid edges.
- Press Space on the top-left cell to start the cruiser; use the arrow keys to move right and press Space twice more so the length-3 cruiser sits across the top row.
- Press Enter on any unoccupied cell adjacent to the cruiser that cannot belong to another ship, to keep your no-touch reasoning visible.
- Move to the third row, last column and press Space; arrow down and press Space again so the length-2 destroyer drops vertically in the rightmost column and satisfies its clue of 2.
- Press Space on the only remaining cell that completes the column-2 clue of 2 while staying diagonally clear of both prior ships — that single segment is the submarine.
- Walk each row and column once more, comparing the count of ship segments against the printed clues and confirming no ship segment touches another diagonally.
- Stop at any cell; the six ship actions will have produced a 940-point score from the starting 1,000.
What Counts as a Diagonal Touch
Diagonal touch is a single-corner contact between two cells that belong to different ship components. On this 5x5 grid, the cells that touch only at a corner are easy to enumerate: (0,0) touches (1,1) diagonally; (0,1) touches both (1,0) and (1,2); and so on across the board. A ship segment at (0,2) — the right end of the top cruiser — diagonally touches (1,3) and (1,1), but those cells stay water here, so the cruiser has no corner contact with the destroyer.
| Ship A cell | Diagonally adjacent cells | Outcome if a different ship sits there |
|---|---|---|
| (0,0) top-left of cruiser | (1,1) | Rejected as a diagonal collision. |
| (0,2) right end of cruiser | (1,1), (1,3) | Rejected if either cell becomes another ship. |
| (2,4) top of destroyer | (1,3), (3,3) | Rejected if either cell becomes another ship. |
| (3,4) bottom of destroyer | (2,3), (4,3) | Rejected if either cell becomes another ship. |
| (4,1) submarine | (3,0), (3,2) | Rejected if either cell becomes another ship. |
Edge-to-edge contact is a separate but related prohibition. Cells that share an edge — for example (0,2) and (0,3) — cannot belong to different ships either; orthogonal contact is also rejected. The validator scans every component for both kinds of neighbors, so the full no-touch ring around each ship is one continuous water border. That is why the row-2 and column-4 zeros matter so much: they extend the natural water ring without any ship action at all, freeing up the diagonal slots that would otherwise become ambiguous.
Scoring, Actions, and Water Marks
The score starts at 1,000 and decreases by 10 for each ship action. A ship action is any Space press that toggles a ship segment on or off, not a water mark and not an arrow-key move. The disclosed solution requires six ship actions to complete: three for the cruiser, two for the destroyer, and one for the submarine. 1,000 minus 6 multiplied by 10 equals 940, which is the puzzle's best score; the result is floored at 0 so no run can go negative.
Water marks placed with Enter do not affect the score or the fleet validator. They are reasoning aids only, intended to track ruled-out cells as you work through the clues and the diagonal rule. Mouse and touch users can click to toggle a ship segment and use the context-menu gesture to mark water.
The board has several built-in safety nets. Restart clears ships, water marks, score, moves, and contradiction state, so a placement that triggers a diagonal conflict can be abandoned without losing the run's information. Double-press Escape opens a shared simulated spreadsheet cover and the fleet is restored unchanged on the next Escape press. The board itself uses semantic buttons in a responsive CSS grid rather than a canvas, and every cell announces its row, column, ship, water, and keyboard-selection state to assistive technology. There is no timer, no random service, no audio, and no account, so the 940-point target depends only on how cleanly you plan six ship actions.
Same Game, Related Fixed Logic Puzzles
The diagonal-separation rule is a recurring idea across fixed logic puzzles. The Tents Puzzle pairs trees with tents while keeping matching pairs apart, including diagonally, which is the same corner-spacing principle applied to a different shape set. Stitches, Thermometers, and Heyawake each layer their own no-touch or connectivity check on a similarly compact grid, and they all reward the same kind of careful planning that gets the cruiser, destroyer, and submarine onto the Lizely five-by-five without corner contact. The rule is identical in spirit; only the shapes being placed change.
For a deeper look at the no-touch and no-bend rules side by side, read Can Ships Bend in Battleships Puzzle? The No-Bend Rule, and for the exact sequence of six ship actions that lands the fleet cleanly, try Battleships Puzzle Tips and Tricks: 6 Moves to 940 Points. Both follow the same fleet, the same clues, and the same corner-spacing contract that this article expands on, and they reinforce the planning mindset that turns the diagonal rule from a restriction into a useful constraint.