A battery is formed by two (or more) pieces lined up on the same file, rank, or diagonal, ready to strike one after the other in the same direction. The front piece attacks first; if the opponent captures it, the piece behind recaptures immediately, often netting extra material since the opponent only expected to face a single attacker.

Why a battery is stronger than two pieces alone

The whole point of a battery is that the front piece can charge in without risk: it’s automatically replaced by the one behind it. Two rooks doubled on an open file, a queen stationed behind a bishop on a diagonal, or a rook behind a knight in front of a mating square: in every one of these cases, the first piece can strike, because the second one guarantees the attack continues.

Example: doubled rooks win a piece

White's two rooks are doubled on the d-file. 1.Rxd8+ all but forces the recapture Bxd8: declining means losing the rook for nothing. Then 2.Rxd8+ collects the bishop.

White has doubled rooks on the d-file, facing Black’s rook and bishop. 1.Rxd8+: the front rook captures the enemy rook and gives check. Black has to recapture with the bishop, 1…Bxd8, or lose the piece for nothing. But White’s second rook, hidden behind until now, takes over: 2.Rxd8+ captures the bishop as well. In the end, White only lost one rook for a rook and a bishop: the battery turned a simple exchange into a clean material gain.

Building and spotting a battery

To build a battery, just stack two long-range pieces on the same attacking line: the more mobile one in front if you want it to strike first, or the more valuable one behind if you want to keep it safe as long as possible. Facing an enemy battery, always be wary of a front piece that looks like it’s offering itself as a sacrifice: it rarely is a gift. In the openings, doubling your rooks on an open file is one of the simplest ways to set up this kind of attack.

Frequently asked questions

Can a battery have three pieces?

Yes, in theory as many as the line can hold. This is sometimes called “Alekhine’s gun” when a queen and two rooks stack up on the same file, a fearsome setup in the middlegame.

Do both pieces need to be the same type?

No, a battery can mix a queen and a rook, a queen and a bishop, or a rook and a bishop, depending on the line involved. What matters is the alignment on the same file, rank, or diagonal, not the piece type.

How do I defend against an enemy battery?

Avoid capturing the front piece without checking what’s standing behind it. If the capture is forced, look to interpose a piece on the line to block the second attacker, or move your threatened piece out of the way before the battery fires.