How to Play Battleship — Rules, Placement Strategy & Hunt/Target Tactics

What Is Battleship?

Battleship is a two-player strategy game where each player hides a fleet of ships on a 10×10 grid and then takes turns calling shots to sink the opponent's fleet. The first player to sink all enemy ships wins.

The game dates back to World War I-era pencil-and-paper games played by French and Russian soldiers. Milton Bradley commercialized it as a board game in 1967, and it's been a staple of game nights ever since. The electronic version arrived in 1977, and now you can play it right here in your browser.

Though luck plays a role, expert Battleship players win far more than 50% of their games. The difference lies in two skills: intelligent ship placement and efficient search patterns.

The Rules

Standard Battleship uses a 10×10 grid (columns A–J, rows 1–10) and five ships:

• Carrier — 5 cells
• Battleship — 4 cells
• Cruiser — 3 cells
• Submarine — 3 cells
• Destroyer — 2 cells

Ships are placed horizontally or vertically (never diagonally) and cannot overlap. Players alternate turns calling a single coordinate. The defender responds with "hit" or "miss." When every cell of a ship has been hit, it's sunk, and the defender announces which ship was lost.

The game ends when one player's entire fleet is sunk.

Ship Placement Strategy

How you place your ships matters more than most players realize. A few principles:

• Avoid the edges and corners. Beginners tend to hug the borders, so experienced opponents will search there first. Place at least some ships in the interior of the grid.
• Don't cluster your ships. If your ships are adjacent, a single lucky hit can lead your opponent to stumble across multiple ships at once.
• Mix orientations. If all your ships run horizontally, your opponent will find them faster once they discover the pattern. Use both horizontal and vertical placements.
• Vary your placement between games. If you always put the carrier in the same spot, observant opponents will catch on.

A meta-level trick: think about where you would search first, and then avoid placing ships there. If you'd target the center, place ships off-center. If you'd sweep the edges, leave the edges empty.

Hunt Mode: Finding the First Hit

The game has two phases: hunt mode (searching for ships) and target mode (sinking a found ship). In hunt mode, your goal is to find a hit as efficiently as possible.

The naive approach — random shots — wastes too many turns. Instead, use a checkerboard pattern (parity strategy). Imagine the grid as a checkerboard. Since the smallest ship is 2 cells long, every ship must occupy at least one "black" square and one "white" square. If you only fire on one color, you can search the entire grid in 50 shots instead of 100.

In practice, you won't need all 50 shots because you'll hit something long before then. But the checkerboard guarantees you'll never waste a shot firing at a square that can't provide new information.

Target Mode: Sinking a Found Ship

Once you score a hit, switch to target mode. Your goal is to determine the ship's orientation and sink it as quickly as possible.

1. First hit: Fire at the four orthogonal neighbors (up, down, left, right). Skip any that are off-grid or already fired upon.
2. Second hit: Now you know the ship's orientation (horizontal or vertical). Continue firing along that line in both directions until you get a miss on each end.
3. Ship sunk: Return to hunt mode. But check: if you got more hits than the sunk ship accounts for, there's another ship adjacent. Stay in target mode for the extra hits.

Important: When you get a hit on an adjacent cell, don't assume it's the same ship. Track hit counts carefully. If you've hit 4 cells but sink a 3-cell cruiser, one of those hits belongs to a different ship.

Probability Density: The Advanced Approach

The most powerful Battleship strategy is probability density mapping. For each empty cell on the grid, calculate how many possible ship placements overlap that cell given the current state of the board (known hits, known misses, and already-sunk ships).

The cell with the highest probability density — the most possible overlapping placements — is your optimal next shot.

You don't need to calculate this perfectly in your head. A rough mental model works well:

• Cells near the center of the grid have higher density early on because more ship orientations fit.
• Cells near known misses have lower density because ships can't pass through misses.
• As the game progresses and ships are sunk, recalculate: only the remaining ships contribute to density.

When only the 2-cell destroyer remains, density shifts dramatically. Suddenly, cells adjacent to tight gaps become the highest-value targets.

The Parity Strategy Explained

The checkerboard (parity) strategy deserves a deeper look because it's the single biggest improvement most players can make.

Here's why it works mathematically: a ship of length n placed on the grid always occupies cells of alternating color on a checkerboard. A 2-cell ship covers one black and one white cell. A 3-cell ship covers two of one color and one of the other. A 4-cell ship covers two and two. A 5-cell ship covers three and two.

Every ship touches at least one cell of each color. So by firing only on one color, you guarantee that every ship will eventually be discovered.

Refine this further: once all ships of length 2 are sunk, you can switch to a sparser pattern. If the smallest remaining ship is 3 cells, you only need to fire on every third diagonal — a pattern that covers the grid in about 34 shots.

Common Mistakes to Avoid

Even experienced players fall into these traps:

• Firing randomly during hunt mode. Random shots feel intuitive but waste turns. Use the checkerboard.
• Abandoning target mode too early. When you hit a ship, sink it before going back to hunting. Leaving a wounded ship means you'll have to re-find it later.
• Forgetting about ship sizes. Track which ships have been sunk. If the carrier and battleship are gone, the longest remaining ship is 3 cells — adjust your hunt pattern accordingly.
• Clustering shots around a miss. A miss tells you the exact opposite of what you want. Move away from misses, don't cluster near them.
• Assuming adjacent hits are the same ship. Two adjacent hits might belong to two different ships. Always verify by counting sunk cells against ship lengths.

Advanced Mind Games

Battleship has a psychological layer, especially in live play. Some strategic considerations:

• Counter-predictable placement. If you know your opponent uses parity, place your 2-cell destroyer on two cells of the same color on their likely checkerboard. This forces them to fire more shots before finding it.
• Touch placement. Place ships so they're adjacent (touching edge-to-edge). When your opponent finds one ship, they may waste shots thinking a neighboring hit is part of the same vessel.
• The corner gambit. Placing a ship in the extreme corner means it's in the last area most parity-based hunters will cover. It's risky — if they search edges, you're found immediately — but it can buy you late-game turns.

Ultimately, optimal Battleship play is about information theory: maximizing the information you gain from each shot while minimizing the information your placement gives away.