How to Play Sea Battle
To play sea battle, each player secretly places five straight ships on a 10 × 10 grid — Carrier 5, Dreadnought 4, Cruiser 3, Submarine 3 and Destroyer 2 — without overlapping and, by default, without touching. Players then take turns calling a square to fire at. The owner answers miss or hit, and names a ship when its last square is hit. The first to sink the whole enemy fleet wins.
The rules, step by step
- 1Hide your fleetPlace five ships on your own 10 × 10 grid — Carrier 5, Dreadnought 4, Cruiser 3, Submarine 3 and Destroyer 2 — each in a straight line across or down.
- 2Keep the ships apartNo two ships may share a square, and by default no two may touch, not even corner to corner. The Ships may touch option allows side-by-side fleets.
- 3Take turns firingCall one square of your opponent's grid by its letter and number, such as E5. You fire first, and the turn passes with every shot.
- 4Answer every shotThe owner of the grid says miss or hit. When the last square of a ship is hit, the owner names the ship that sank, and here it is revealed.
- 5Never fire at the same square twiceA square already fired at can tell you nothing new, so it does not count as a shot — choose another.
- 6Sink the whole fleet to winThe first side to sink all five of the other side's ships wins, the moment the last one goes down.
Try it — the rules above, running
Your waters5 of 5 ships placed
Drag a ship to move it, tap it to turn it. Ships may not touch, even at the corners.
New game deals you a random fleet: drag a ship to move it, tap it to turn it, or press Shuffle, then Start battle. You fire first — tap a square in the enemy waters, or aim with the arrow keys and fire with Enter. Hint marks the likeliest square, and the ⋯ menu holds today’s shared fleet, the opponent’s level and the two rule options.
Your statistics · Normal
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- Best streak
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Hunts on a checkerboard spaced for the smallest ship left, then works along the line of a hit. A battle you abandon counts as a loss. Kept in this browser only.
Today’s game
The computer’s fleet for today is placed from the date, so everyone who plays it hunts the same five ships — compare how many shots you needed.
Keyboard
- Arrows
- Aim
- Enter / Space
- Fire
- 1 – 5, R, S, B
- Setup: lift, turn, shuffle, start
- H
- Hint
- N
- New game
- F
- Full screen
How do you set up your fleet?
- 1Draw two gridsOne 10 × 10 grid holds your own fleet; the other records your shots at your opponent. Columns are lettered A to J and rows numbered 1 to 10.
- 2Place the five shipsCarrier 5, Dreadnought 4, Cruiser 3, Submarine 3 and Destroyer 2 — each in a straight line across or down, wholly inside the grid.
- 3Check the spacingNo two ships may overlap. Under the standard rule on this page they may not touch either: leave at least one square of water all round every ship, corners included.
- 4Keep it hiddenYour opponent must never see your grid. On this page the computer never looks at it: all it knows is where it has fired and what it hit.
What does the owner say after each shot?
| Answer | When | What the shooter learns |
|---|---|---|
| Miss | The square is open water | Nothing is on that square |
| Hit | The square is part of a ship | A ship is there, but not which one |
| "You sank my Cruiser" | The last unhit square of a ship is hit | Which ship it was — and on this page, exactly where it lay |
How does a game of sea battle end?
The moment one side's fifth ship sinks. There are no draws: the shots alternate, so one fleet always goes down first. You fire first on this page, which is a small edge — if you and the computer would each need the same number of shots, yours lands first.
What changes with an extra shot after a hit?
With Extra shot after a hit switched on, a hit — sinking included — earns the shooter another shot straight away, and the same goes for the computer. A miss still passes the turn. Games get shorter and swingier: whoever finds a ship can often finish it in a single turn.
How do you win more often?
- Hunt on a checkerboardEvery ship is at least two squares long, so firing only at one colour of a checkerboard — 50 squares — cannot miss a whole ship. Once the Destroyer is gone, every third diagonal is enough: 34 squares.
- Start in the middleOn an empty grid a centre square can be covered by 34 different ship placements and a corner by only 10, so early shots in the middle are likelier to find something.
- Finish every ship you hitTry the four squares around a lone hit; once two hits line up, fire along that line in both directions until the ship sinks. A hit left unfinished is information thrown away.
- Cross off the water round a sunk shipWhen ships may not touch, every square around a sunk ship is empty — 10 for a Destroyer in open water, 16 for a Carrier. Using that is worth about 7 shots a game to the Hard opponent.
- Keep your own fleet unpredictableYour fleet is dealt at random, and a random fleet gives a hunter nothing to exploit. If you place ships yourself, avoid patterns such as every ship along one edge or all five facing the same way.
Common questions about sea battle
- Can you move your ships during a game of sea battle?
- No. Once the first shot is fired your fleet stays where it is until the game ends. On this page you can drag, turn and shuffle your ships freely until you press Start battle.
- What is the difference between a hit and a sink?
- A hit means one square of a ship has been struck. The ship sinks only when every one of its squares has been hit, and only then does its owner say which ship it was.
- How big is the grid in sea battle?
- Ten squares by ten, 100 in all, with columns A to J and rows 1 to 10. A full fleet of five ships covers 17 of them.
Ready to stop reading? Play sea battle on the full board, with controls and statistics tailored to that game.