Sea Battle: sink the ships against the computer
Sea battle: hide your fleet on a 10 × 10 grid and take turns with the computer firing at squares like B7. First to sink every enemy ship wins – the classic pencil-and-paper game, without the paper.
Source: Wikipedia: Battleship (game) – 10 × 10, Flotte 5-4-3-3-2 (1990), Geschichte. Updated: .
How it is calculated
How to play Sea Battle against the computer
- Place your fleet: tap your grid to place the next ship; “Rotate” switches between horizontal and vertical. In a hurry? Use “Random placement” or just press start – any missing ships are placed at random.
- Fire: tap a square in the computer’s waters. A dot means miss, a red cross means hit. Once every square of a ship is hit, it’s sunk.
- Take turns: then the computer fires at your fleet. The first to sink all enemy ships wins.
Rules and variants
The grid is 10 × 10, with columns A–J and rows 1–10. Ships lie horizontally or vertically, never diagonally. Two common fleets are available:
- 5 ships of 5, 4, 3, 3 and 2 squares (17 in total) – the line-up of the well-known 1990 board game edition.
- 10 ships of 5, 4, 4, 3, 3, 3, 2, 2, 2 and 2 squares (30 in total) – a classic pencil-and-paper fleet from Germany.
Two house rules can be switched on: ships may not touch (not even corner to corner – the game then marks the squares around a sunk ship as empty) and fire again after a hit. On paper you agree on these before you start; here they apply to you and the computer alike.
The three computer levels
- Easy fires at random squares.
- Medium fires at random until it hits, then searches around the hit – the way most people play.
- Hard works out every position the remaining ships could still be in before each shot and fires at the square covered by the most of them. Beating it takes luck and an unusual layout.
Points and challenges
A win scores 1,000 × ship squares ÷ your shots: hit with every shot and you get 1,000; need twice as many shots and you get 500. “Share result” sends a link with the same computer fleet and rules, so friends can try to sink it in fewer shots.
Tips
- Fire in a checkerboard pattern: the smallest ship is two squares long, so every ship covers at least one square of each colour.
- After a first hit, try the four neighbours; after a second, keep going along that line.
- Don’t park every ship on the edge – strong players check the edges on purpose.
Limits and privacy
The computer can’t see your layout; it only knows what you know about its waters. Its fleet is drawn with the browser’s random number generator. Settings, wins and best scores are kept in your browser’s localStorage (key schiffeversenken) and never sent to a server. It isn’t a two-player game on one screen, because both fleets would be visible.
More strategy games against the computer: Four in a Row and Checkers.
Frequently asked questions
How do you play sea battle?
Both sides hide their ships on a 10 × 10 grid and take turns calling squares such as C5. The answer is miss, hit or sunk. The first player to sink the whole enemy fleet wins.
What ships are in a sea battle game?
The 1990 board game edition uses five ships of 5, 4, 3, 3 and 2 squares. Many paper versions use more ships – for example ten ships from 5 down to 2 squares. Both fleets can be chosen here.
Can ships touch each other?
That’s up to the players. Many paper rules forbid touching, even diagonally. Here you switch that rule on or off with a checkbox.
Can I play sink the ships online against the computer?
Yes, right here in your browser – free, with no sign-up and no app. The computer plays at three levels, from random shots to probability-based targeting.
What is the best strategy for sea battle?
Fire in a checkerboard pattern until you hit, then follow the line. When placing, avoid obvious patterns and don’t put every ship on the edge.
Sources and legal basis
- Wikipedia: Battleship (game) – 10 × 10, Flotte 5-4-3-3-2 (1990), Geschichte
- MDN: Pointer events
- MDN: Window.localStorage
- MDN: Crypto.getRandomValues()
As of: · Editorial policy
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