Battery

A battery is two or more of your own pieces deliberately stacked on the same rank, file, or diagonal, both aimed at the same target. Nothing about it is hidden — you build it on purpose, over one or more moves, specifically so that when the front piece finally makes contact, there's a second attacker already backing it up.

The arithmetic that makes a battery work

A single attacker against a single defender is an even fight — whoever captures first, the other side recaptures, and the material stays balanced. A battery breaks that balance on purpose: two attackers against one defender means the defender runs out of pieces to recapture with before the attacker runs out of pieces to keep capturing with. The front piece can walk into what looks like an even trade, because the second capture — made by the piece that was waiting behind it — is where the actual profit comes from.

Which piece belongs in front

There's a real decision to make about ordering, and it isn't automatic. Putting your more valuable piece (often the queen) in front means it does the initial capturing and is the piece exposed to any immediate tactical reply, while the piece behind it stays protected until it's needed. Putting the less valuable piece in front is usually safer, since it risks less if the sequence doesn't go exactly as planned — the standard guidance is to lead with whichever piece you're more willing to see traded first, not automatically the strongest one.

Building a battery takes time — and telegraphs your plan

Unlike most of the tactics on this site, a battery is rarely a single surprising move; it's usually assembled over two or three moves as pieces reposition onto the same line. That means the opponent typically sees it coming and has a chance to reinforce the target square before it's ready. A battery is worth building specifically when you can add a second defender to the target faster than the opponent can add a third one, or when the target simply can't gain any more defenders at all.

Battery vs. the tactic that's easy to confuse it with

The mechanics look almost identical to an x-ray attack — two of your pieces on the same line, one behind the other — but the difference is entirely about intent and visibility. A battery is built on purpose and is visible to both players well before it matters. The hidden version, where a piece is attacking through another piece without either side having deliberately arranged it, is worth its own separate look.

Defending against a battery aimed at you

Since a battery is usually visible well before it fires, the defending side has real options that don't exist against a sudden tactic: add a second defender of your own to the target square, trade off the front attacking piece while it's still reachable, or block the line entirely with a piece the attacker can't easily remove. Waiting until the battery is fully assembled and only then looking for a defense is the mistake — the best moment to respond is while the second attacking piece is still repositioning, not after.

See x-ray attack for the version of this same doubled-line idea that isn't built on purpose and is much easier for both sides to miss.