How to play Sea Battle

Sea Battle is the classic naval guessing game for two. Each side hides a fleet of ships on a 10 x 10 grid of sea, then the two take turns calling squares on the other's grid. Every shot is answered with a miss, a hit or a sunk ship, and the first to send the whole enemy fleet to the bottom wins.

For generations it was played with pencil and squared paper in school notebooks, and the classic rules here are that notebook game: ten ships of four sizes that may never touch, and a hit that lets you fire again. Luck decides where your first shots land, but after that it is a game of deduction. Every miss rules out water, every hit narrows down where the rest of the ship can be, and a good player wastes far fewer shots than a careless one.

How to play on skill.games

In the settings popup choose a difficulty (Easy, Normal, Hard or Crazy) and the rules (Classic or Five ships), then press PLAY. A match has two parts.

1. Place your fleet. Your empty sea is shown with your ships waiting in the dock below it (beside it when the screen is held sideways).

• Drag a ship from the dock onto your sea. On a touch screen the ship rides a little above your finger so you can see where it goes; a green shadow shows where it will land, a red one shows it cannot go there.
• Tap a ship on the sea to turn it between lying across and standing up. It turns about the square you tapped and slides along if it needs room.
• Tap a ship in the dock to send it to a free spot of its own choosing.
• Drag a placed ship to move it. Drop it somewhere it does not fit and it goes back where it was.
• RANDOM lays out the whole fleet for you, CLEAR returns every ship to the dock, and FIGHT starts the battle once every ship is at sea.

2. Battle. On a phone held upright the computer's sea is the large board on top and your own fleet is the smaller board below it; held sideways, or on a tablet or computer, the two seas sit side by side.

• To fire, tap a square on the computer's sea. You can also press, slide the crosshair to the square you want and lift your finger to fire.
• A dot marks a miss, a burning cross marks a hit, and a sunk ship is shown in full with every square crossed out.
• Squares you have already fired at cannot be fired at again.
• The row of small bars above each sea shows that fleet's ships: bright bars are still afloat, crossed-out ones are sunk. Watching the computer's bars tells you which sizes you still have to find.
• The latest shot on each sea is outlined, so you can always see where the computer just fired.

The menu button in the top-left corner pauses the game and lets you resume, start a new game or switch the sound on or off. The battle is saved at every turn, so an unfinished game can be continued next time with CONTINUE.

When one fleet is gone, the computer's remaining ships are revealed and the results screen shows the outcome, the ships each side sank, the shots each side fired and their accuracy, plus your statistics for that difficulty and those rules: wins, losses, win rate, current streak and best streak.

Rules

Both rule sets use a 10 x 10 sea, with columns lettered A to J and rows numbered 1 to 10. Ships lie in a straight line, across or down, never diagonally. You always fire first.

Classic (the default) is the traditional Russian game:

• The fleet has ten ships: one of four squares, two of three, three of two and four single-square boats.
• Ships may not touch, not even at a corner. There is always at least one square of water between two ships.
• A hit fires again. After a hit or a sinking you shoot again; the turn passes only on a miss. A lucky run can sink several ships in one turn.
• When a ship is sunk, every square of water around it is marked, on both seas, because no other ship can be there.

Five ships is the version most popular in English-speaking countries:

• The fleet has five ships, of five, four, three, three and two squares.
• Ships may touch each other, side by side or end to end.
• One shot per turn, hit or miss.
• A sunk ship is announced and shown, but the water around it is not marked, since a neighbouring ship could be right next to it.

In both, the first side to sink every ship of the other wins. There are no draws.

Strategy tips

• Hunt on a pattern, not at random. Every ship of two squares or more covers at least one square of a checkerboard pattern, so firing only at "black" squares finds them in half the shots. Once only longer ships remain, spread the pattern wider: to find a ship of four, every fourth square on each diagonal is enough.
• Finish what you hit. After a hit, try the four squares around it. Once you have two hits in a line, keep going along that line in both directions until the ship sinks; it cannot bend.
• Use the empty space. A large ship needs a long stretch of open water. Areas broken up by misses can only hide small boats, so leave them for later and search where the big ships still fit.
• In Classic, think in rings. Ships cannot touch, so the squares diagonal to any hit are always water, and a sunk ship clears a whole ring around itself. Each sinking makes the next search easier.
• Count what is left. The bars above the computer's sea tell you exactly which sizes are still afloat. If only single-square boats remain, patterns no longer help; if a four-square ship is still out there, look for the gaps where it fits.
• Hide your fleet well. Many players crowd the middle. Long ships along the edges and small boats scattered in open water are harder to find, and in Classic, keeping ships apart wastes fewer of the opponent's shots on rings.
• Do not chase lost causes. If a square is surrounded by misses on all sides and every remaining ship is longer than the gap, nothing can be there. Skip it.

Difficulty levels

The computer never looks at your ships; it only knows what you know: its own hits, misses and the ships it has sunk.

• Easy: fires at random. After a hit it tries a square next to it, but without following the line of the ship, and half the time it forgets the hit and fires at random again. Its fleet is placed at random.
• Normal: hunts at random, but once it hits a ship it follows the line and finishes it. Its fleet is placed at random.
• Hard: hunts on a checkerboard-style pattern and only where a ship can still fit, and after a hit it turns towards the longer stretch of open water. It places its long ships along the edges of its sea.
• Crazy: works out every way each remaining ship could still lie, given every miss, hit and sinking, and fires at the square most of them cover. It finishes wounded ships first. It places its fleet away from the squares a careful shooter checks first, which makes its ships harder to find.

Modes

• Classic: ten ships (4, 3, 3, 2, 2, 2, 1, 1, 1, 1), no touching even at corners, a hit fires again, the water around sunk ships is marked. The traditional game and the default.
• Five ships: five ships (5, 4, 3, 3, 2), ships may touch, one shot per turn. A slower, more even game in which every shot counts.

Each mode keeps its own statistics for every difficulty.