Battleships is also called Bimaru or Battleship Solitaire. It is a puzzle for one player, based on the old guessing game. Here you do not fire at random. You use the numbers to work out where every ship is.
The rules
- The ship list shows every hidden ship and how long it is.
- Each ship lies in a straight line, across or down.
- The number next to a row or column says how many ship boxes it has.
- If a row or column has no number, you are not told how many ship boxes it has.
- Ships never touch each other, not even at the corners.
- Some boards show a few ship parts or sea boxes at the start. These stay as they are.
- A ship part shown at the start also shows its shape: a ship of 1 box, an end or a middle part.
- You do not have to mark every sea box. Only the ships count.
Quirk uses the classic rules of the puzzle.
A worked example
Example 1: a 3 by 3 board
The ship list has 1 ship of 2 boxes and 1 ship of 1 box. The row numbers are 2, 0 and 1, from top to bottom. The column numbers are 1, 1 and 1. A ship part is shown at the start in row 1, column 1.
- Row 2 shows 0. Mark all 3 of its boxes as Sea.
- Row 1 needs 2 ship boxes. One of them is the ship part in column 1.
- Row 2 is all sea, so no ship can go down from row 1.
- Say the second ship box were in column 3. Then row 1 would hold 2 ships of 1 box each.
- The list has only one ship of 1 box. So the second ship box must be in column 2.
- Columns 1 and 2 of row 1 now make the ship of 2 boxes. Mark row 1, column 3 as Sea.
- Columns 1 and 2 now have their 1 ship box each. So row 3, columns 1 and 2 are Sea.
- Row 3 needs 1 ship box, and only column 3 is left. Place the ship of 1 box there.
- Check: every number matches, and the two ships do not touch. The puzzle is solved.
Example 2: a 4 by 4 board
The ship list has 1 ship of 3 boxes and 1 ship of 1 box. The row numbers are 3, 0, 1 and 0. The column numbers are 1, 1, 1 and 1. A ship part is shown in row 3, column 4.
- Rows 2 and 4 show 0. Mark all their boxes as Sea.
- Row 3 needs 1 ship box, and it already has the one in column 4. Mark the rest of row 3 as Sea.
- The ship part in row 3 has sea above it, below it and to its left. So it is the ship of 1 box.
- The ship of 3 boxes is still to place. Row 1 is the only row with room for it.
- Column 4 already has its 1 ship box. So row 1, column 4 is Sea.
- That leaves columns 1, 2 and 3 in row 1. Place the ship of 3 boxes there.
Beginner techniques
Start with the zeros
A row or column with 0 has no ship boxes at all. Mark it all as Sea first. This often splits the board into smaller parts.
Fill or close a row
If a row already has all its ship boxes, the rest of that row is sea. If a row needs every unmarked box to reach its number, all of them are ship. The same works for columns.
Put sea around ships
Ships never touch, not even at the corners. So the boxes on the diagonals of any ship box are always sea.
When a ship is finished, mark sea all around it. A ship is finished when it cannot grow longer, for example when no ship still to find is longer.
Read the starting shapes
A ship part shown at the start tells you more than you might think. A left end means the box to its right is ship too. A ship of 1 box gets sea all around it.
Place the longest ship first
The longest ship has the fewest places to go. Look for rows and columns with enough room and a big enough number. Sometimes only one place is left.
Common mistakes
- Letting two ships touch at a corner.
- Putting two ships side by side. Together they make one longer ship, which may not be in the list.
- Forgetting to count the ship parts shown at the start in the row and column numbers.
- Thinking a row with no number has no ships. It just means you are not told.
- Marking a ship that goes around a corner. Ships are always straight.
Questions
Is Battleships the same as Bimaru?
Yes. Bimaru and Battleship Solitaire are other names for the same puzzle. The rules are the same.
Do I have to mark every sea box?
No. You only need to place all the ships. Sea marks are there to help you keep track.
Does every puzzle have one answer?
Yes. Every Battleships board in Quirk has exactly one answer. You can find it by thinking, step by step.
What sizes are there?
Quirk has boards of 4 by 4, 6 by 6 and 8 by 8. The bigger boards have more ships to find.
Is it good for beginners?
Yes. Rows and columns with 0 give you an easy start. Short lessons in Quirk show the first steps on tiny boards.
Related puzzles
Playing it in Quirk
Tap a box once to mark it as Ship. Tap again for Sea, and once more to make it empty. Drag across boxes to mark many of them as Sea at once.
Turn on Notes if you want a tap to add a note instead of a mark. The Still to find list shows which ships are left. Hints, undo and reset are there if you get stuck.
