Battleship

Battleship is the hidden-ship guessing game that began as a pencil-and-paper game around the First World War, was sold as printed score pads from the 1930s, and became the iconic plastic grid game when Milton Bradley released it in 1967. Two players secretly place 5 ships on their own grid; take turns calling out coordinates (“B-4”) to attack opponent grids; the first to sink all opponent ships wins. The game has been a household staple for over 50 years and has spawned movies, TV shows, video games, and academic studies on optimal targeting algorithms.

How to play

• Setup: each player has a 10×10 grid, traditionally labeled A-J (rows) and 1-10 (columns). Our version has no coordinate labels: you simply click a cell.
• Ships to place: Carrier (5 cells), Battleship (4), Cruiser (3), Submarine (3), Destroyer (2). Total 17 cells per side.
• Ships can be horizontal or vertical but not diagonal. They can’t overlap or extend off the grid.
• Players take turns calling out a grid coordinate (e.g., “C-7”).
• The opponent responds “Hit” (if a ship occupies that cell) or “Miss”.
• When all cells of a ship are hit, the opponent announces “You sunk my Battleship/Carrier/etc.”
• First to sink all 5 of opponent’s ships wins.
• In our version: click your own grid to place each ship in turn (press R or the Rotate button to switch between horizontal and vertical), or press Random Placement. Then click a cell in Enemy Waters to fire. The CPU fires back after every shot, one shot each, even when you score a hit. The game tells you when you sink a ship and counts your total shots. Press New Game (or N) to start over.

Beginner strategy

• Don’t place ships at edges. Edge ships are easier to find by methodical searching.
• Don’t cluster ships. If one is found, nearby ships become easier to find through “neighbor” guessing.
• Once you get a hit, search adjacent cells. Ships are linear, so a hit means the rest of the ship is in one of 4 adjacent cells.
• Spread early attacks. Attacking every other cell (a checkerboard pattern) efficiently covers the grid.
• Track misses. Knowing where a ship ISN’T narrows the search space.

Intermediate strategy: hunt and target

Battleship strategy has two phases — Hunt mode (no current contact) and Target mode (you’ve hit something).

• Hunt mode. Use a checkerboard pattern. Since the smallest ship is 2 cells, checkerboard guarantees finding any ship within ~50 guesses.
• Target mode (post-hit). Try cells in cardinal directions from the hit. Once a second hit lands, you know the ship’s orientation. Continue along that line until you sink it.
• Don’t waste turns missing the same way. Failed cardinal attempts narrow the ship’s direction.
• Resume hunt after sinking. Once a ship is sunk, return to your hunt pattern.
• Track ship lengths sunk. When the 5-cell Carrier is gone, you know the remaining ships are smaller. Re-target accordingly.

Advanced strategy: probability targeting

• Calculate ship-position probabilities. For each unattacked cell, count the number of valid ship placements that would include that cell. Attack the highest-probability cell first.
• Account for known ship sizes. If only 3-cell and 5-cell ships remain, probability calculations focus on those sizes only.
• Symmetry breaking. Use the parity of grid cells to bias your hunt.
• Concealment placement. Place your own ships in patterns that look like random placement. Algorithmically optimal placement often “looks” wrong.
• Hunt smarter: computer simulations of the game have found that probability targeting sinks a whole fleet in noticeably fewer shots on average than a plain hunt-and-target approach.

Ship placement strategy

• Avoid edges and corners. Corner placements are statistically more findable.
• Don’t align all ships. Mix horizontal and vertical orientations.
• Don’t bunch ships. Spread out — adjacent ships make detection cascading.
• Asymmetric placements. Avoid placing ships in symmetric patterns; some humans subconsciously expect symmetry.
• Mix sizes. Place small ships in the most “obvious” spots (random clusters); leave the Carrier in less expected locations.
• Against our CPU: it hunts by firing at random cells on a checkerboard pattern, then tries the four neighbours after each hit until the ship sinks. It doesn’t read your placement habits, so where you put ships matters less than against a human.

Battleship history

• ~1910s — Pencil and paper: the guessing game is played on hand-drawn grids around the time of the First World War.
• 1930s — Pad games: printed versions appear, including Salvo (1931); Milton Bradley later published its own pad-and-pencil Battleship.
• 1967 — Plastic version: Milton Bradley releases the iconic plastic grid game with pegs.
• 1977 — Electronic Battleship: Milton Bradley releases a computerized version with sound effects.
• 2012 — Battleship film: Hasbro adapts Battleship into a major motion picture. Universally panned but spawns merchandise.
• Modern era: Battleship remains in print, in countless digital adaptations, and a staple of family game collections.

Common mistakes

• Random attacks. Without pattern, you waste turns.
• Missing adjacent cells. After a hit, attacking distant cells instead of cardinal-adjacent ones is wrong.
• Placing ships predictably. Corner ships, edge alignments — easier for skilled opponents to find.
• Forgetting which ships are sunk. Remaining cells should be searched against remaining ship sizes.

Variants

• Salvo. Each player attacks multiple cells per turn (3-5).
• Bigger boards. House rules with a larger grid and more ships.
• Electronic Battleship. A computerized unit with sound effects.
• Battleship Galaxies: a space-themed spin-off board game.
• Sea Battle apps: turn-based mobile multiplayer Battleship descendants.

FAQ

• Q: How many ships? A: 5 — Carrier (5), Battleship (4), Cruiser (3), Submarine (3), Destroyer (2). Total 17 cells.
• Q: Can ships be placed diagonally? A: No. Ships are placed horizontally or vertically only.
• Q: Best opening shot? A: A checkerboard pattern guarantees hitting every ship, even the 2-cell Destroyer, within 50 shots. Probability targeting usually does better still.
• Q: Why no “you sunk my battleship” until all cells hit? A: The rules say the opponent must announce when a ship is fully sunk. Players track hits to know when each ship’s cells are all gone.

For other hidden-info games, try Minesweeper, Mastermind, Hangman, or Chess.