Sea Battle

Sea Battle is a two-player game on two ten-by-ten grids. Each player hides a fleet of five ships, five, four, three, three and two squares long, on their own grid; then you take turns calling one square of the other's. A ship sinks when every square is hit, and sinking the whole fleet first wins, in ten to fifteen minutes.

Your first game

1. Each player has their own sea: a grid ten columns by ten rows. You cannot see your opponent's, and they cannot see yours.
2. First you both place your fleets, at the same time. Five ships, of 5, 4, 3, 3 and 2 squares. Each ship lies in a straight line, across or down, and must fit on the board. Ships may touch; they may not overlap.

Before

After

3. Neither of you is waiting for the other here — you both arrange your fleets at once, and you may pick a ship back up and move it for as long as you have not finished. Once both fleets are down, the shooting starts.

4. Then you take turns firing, one shot per turn, at a square of your opponent's sea. They tell you what it found, and the turn passes.

Before

After

5. A hit does not give you another shot. The turn passes after every shot, whatever it found.

Before

After

6. Sink every one of your opponent's ships to win.

The rules

Two seas, ten by ten

Each player has a grid of ten columns and ten rows, one hundred squares. You see your own fleet and every shot fired at it, and of your opponent's sea you see only what your own shots have found.

Nothing else crosses between you. A square you have not fired at is a square you know nothing about.

The fleet is five ships

Five ships, of 5, 4, 3, 3 and 2 squares. That is seventeen squares of ship in one hundred squares of sea, and the two ships of three squares are why a hit of length three tells you less than you would like.

A ship lies in a straight line — across or down, never diagonally — and every square of it must be on the board.

Ships may touch. Two ships side by side, or end to end, are legal here. This is the rule that differs most between houses, and on this site the permissive version is the one in force: only overlapping is refused.

Both fleets go down at once

Setup is not a turn order. Both of you place at the same time, and neither waits for the other to finish before starting.

While you are still placing, you may pick up a ship you have already put down and move it. Once your last ship is placed your fleet is fixed and you cannot touch it again. When both fleets are finished, the match moves to firing.

The ships go down in one order — 5, 4, 3, 3, then 2 — and the board tells you which one it is asking for, marks every square it could start on, and turns it across or down at your word.

You have two minutes for each placement and thirty seconds for each shot. The two are different on purpose: arranging a fleet is a decision and a shot is one tap, and two minutes of dead air per shot is what makes a quick game feel slow.

If one of you has not placed when the setup clock runs out, that player forfeits — and only that player. If neither has, the match is a recorded draw, because handing the win to whoever happened to be seated first would be a false result on the ladder.

A shot is one square, and the turn always passes

On your turn you name one square of your opponent's sea. They answer, and the turn passes — whether you hit or missed.

This is the rule most people arrive expecting to be different, because many household versions give you another shot for a hit. Here, a hit and a miss cost exactly one turn each.

You may not fire at a square you have already fired at; this board does not offer one. You may not fire outside the board.

A ship sinks when every square of it is struck

You are told hit or miss for each shot, and nothing more. You are not told which ship you hit, or how long it is.

When you have struck every square of one ship, that ship sinks, and only then is it shown to you whole — all of its squares, in your opponent's colour. That is the moment a run of hits stops being a guess and becomes a length.

Sinking the whole fleet wins

When every one of a player's five ships has been sunk, the other player has won.

The fleet

Commonly got wrong

"I hit — don't I get another shot?"

Not here. The turn passes after every shot, hit or miss. Many of the boxed versions give you a second shot for a hit; this site does not.

"Can my ships touch each other?"

Yes. Side by side, end to end, corner to corner — all legal. Only overlapping is refused. Some houses play that ships must have a clear square between them; that is not the rule here.

"Can I put a ship diagonally?"

No. Across or down only.

"It said hit but not which ship. Is something broken?"

No — that is the game. You learn what you hit when it sinks, and not before. With two ships of three squares in the fleet, a three-hit run is genuinely ambiguous until one of them goes down.

"Why can I not move my ship any more?"

Because your fleet is finished. You may rearrange freely while you are still placing, and not at all once the last ship is down.

"Do I have to wait for my opponent to finish placing?"

No. You both place at once. You only wait once your own fleet is down.

Sources

The board, the fleet of 5, 4, 3, 3 and 2, and sinking a ship by striking every square of it follow the published rules of the boxed game — Hasbro's Battleship instructions, whose fleet is exactly those five lengths on a ten-by-ten grid.

Two rules here are this site's and not theirs, and both are marked where they are taught. The turn passes after a hit, where many household and boxed versions grant another shot. And ships may touch, where some houses require a clear square around each one. Neither is a variation this page is quiet about, because they are the two things a player arrives already believing.

Battleship is a registered trademark of its owner. It is named here only to identify the published instructions this fleet follows; this game is Sea Battle, and this site is not affiliated with or endorsed by the trademark holder.

Updated 22 September 2026