Battleship Game

Hide your five ships on a 10 × 10 grid, then take turns firing at the computer's waters. Sink the whole enemy fleet before it finds yours.

How to use the Battleship Game

1. Arrange your fleet. Your ships start in random positions. Press Shuffle ships for a new layout, or pick a ship and click your board to move it. Use Rotate (or R) to switch between horizontal and vertical.
2. Choose the rules. Pick the computer's level and who fires first. Optionally forbid touching ships or allow a bonus shot after each hit.
3. Start the battle and click a square in Enemy waters to fire. A red marker is a hit, a small dot is a miss.
4. Hunt down damaged ships. After a hit, fire at the neighbouring squares to find which way the ship runs. You are told when a ship is sunk.
5. Sink all five enemy ships before the computer sinks yours to win.

Battleship rules at a glance

• Both players secretly place their ships horizontally or vertically on a 10 × 10 grid. Ships can't overlap or leave the board.
• Players take turns naming a square, such as B7, to fire at. The defender answers "hit" or "miss".
• When every square of a ship has been hit, the ship is sunk and the defender says which ship it was.
• The first player to sink all five enemy ships wins.

How the computer opponent works

Easy picks random squares it hasn't tried yet. On average, random shooting needs well over 90 shots to sink a fleet on a 100-square board.

Normal uses the classic hunt and target method. While hunting it only fires on squares of one checkerboard color, because even the smallest remaining ship must cover one of them. After a hit it switches to target mode, tries the four neighbours and, once it has two hits in a row, keeps firing along that line until the ship sinks.

Hard builds a probability map before every shot. For each ship still afloat it counts every horizontal and vertical position that fits with the misses and sunk ships so far. Positions that pass through unexplained hits are weighted much more heavily. It then fires at the square covered by the most positions. This approach usually finishes a game in noticeably fewer shots than hunt and target.

Tips to beat the computer

• Use parity. Fire on a checkerboard pattern while hunting. When the Destroyer is sunk, every remaining ship is at least 3 long, so you can space shots three squares apart.
• Finish what you start. After a hit, find the direction of the ship before going back to hunting. A half-damaged ship gives you free information.
• Read the sunk messages. If you sink a 3-square ship but scored 4 hits in that area, another ship is right next to it.
• Hide well. Against Hard, edges and corners are a little safer than the center, but don't put every ship on the edge or the pattern becomes predictable.

Frequently asked questions

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