--- title: "The cannon · Questions · Xiangqi Master" description: "Everything about the xiangqi cannon: the screen rule, what counts as a screen, cannon mates, and why a lone cannon cannot win." url: https://xiangqimaster.com/blog/topics/cannon source: Xiangqi Master (https://xiangqimaster.com) license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) --- # Questions about the cannon The cannon is the piece that makes xiangqi its own game, and the piece that generates the most questions. It moves like a chariot and captures like nothing else on any board. What counts as a screen for a cannon? Any single piece of either colour, of any type, standing between the cannon and its target. Exactly one is required — no more, no fewer. Why can't a lone cannon checkmate? Against a bare general in an empty palace there is nothing to jump over, so a lone cannon cannot even give check, let alone mate. What is the Central Cannon in xiangqi? The Central Cannon is 炮二平五, moving a cannon to the central file to attack the opposing general through the central soldiers. How do you defend against a cannon in xiangqi? Remove the screen, add a second one, block the line, or capture the cannon. Removing the screen is the answer most players overlook. What is 馬後炮 (horse behind cannon)? 馬後炮 is the classic mate: a horse in front of the general with a cannon behind it on the same line, using the horse as its screen. What is 重炮 (double cannon)? 重炮 is two cannons stacked on the same file as the general, with the front one acting as the rear one's screen. Can a cannon move without a screen? Yes. Moving requires a completely clear line — exactly like a chariot. Only capturing needs a screen. How should I use my cannons in the opening? Put one on a line that matters — usually the central file — and avoid moving either of them three times before your chariots have moved once. Why do cannons get weaker in the endgame? Because a cannon needs a screen to capture, and every trade removes a potential screen. An empty board gives a cannon nothing to work with. How do a chariot and cannon work together? The chariot opens and controls lines while the cannon fires across screens on them. Together they are the standard attacking pair against the palace. What is a cannon on the bottom rank called, and is it strong? A cannon dropped to the opponent's back rank (沉底炮) attacks along the rank behind the palace and is a standard attacking device. Does putting a piece in the way stop a cannon? It depends on the count. Adding a piece to an empty line switches the cannon on; adding one to a line that already has a screen switches it off. What is a hollow cannon (空頭炮)? 空頭炮 is a cannon on the general's file with the line completely clear between them — a powerful positional threat, not an immediate check. Can you trap a cannon in xiangqi? Yes, though less often than a horse. A cannon cannot go around obstructions, so one deep in enemy territory can be cut off and won. Cannon or chariot — which is better? The chariot, clearly. It is worth about 9 against the cannon's 4.5, because it captures along any clear line with no screen required. What is the cannon called in Chinese — 炮 or 砲? Both are used and both mean cannon. 砲 has the stone radical, from siege engines that threw rocks; 炮 has the fire radical, from gunpowder. Why do chess players struggle with the cannon? Because it inverts the chess instinct: an open line means no attack, and blocking a line can create one instead of stopping it. Can a cannon pin a piece in xiangqi? Yes, and it works backwards from a chariot pin: the pinned piece is the cannon's screen, so moving it disables the cannon rather than exposing a capture. Should I keep both cannons or trade one? Keep both while the board is full, especially if you are attacking — two cannons make 重炮 possible. Trade one heading into an endgame. How do I stop missing cannon threats? Scan every line where a cannon faces your general or a valuable piece and count the pieces in between. Two seconds per cannon, every move. Can a cannon defend a piece in xiangqi? Yes, but only across a screen, the same way it attacks. A cannon defends a piece by being able to recapture on that point through exactly one piece in between. What is a cannon fork in xiangqi? A cannon fork is a single cannon move that creates two capture threats at once, typically by landing on a line where two different pieces each sit one screen away. How many cannons does each side start with in xiangqi? Two per side, placed on the third rank directly in front of the horses, with a completely open line across the board from the very first move. What is a cannon sacrifice in xiangqi? Giving up a cannon deliberately to open a line, remove a defender, or force the enemy general into a mating net, in exchange for a decisive follow-up attack. How do two cannons attack on different files in xiangqi? Rather than stacking on one file, two cannons can split across two files, each threatening a separate point near the palace so the defender cannot answer both. How does a cannon behave differently in the middlegame? At its strongest: plenty of pieces still on the board to act as screens, and enough of them are still mobile enough to create shifting, hard-to-track threats. Why do players avoid trading cannons too early in xiangqi? Because early on a cannon is close to its peak value, with plenty of screens available. Trading it off before it has done any work gives up that potential for nothing. How do you know if a cannon is good or bad in a given position? Count its available screens and its actual targets, not just its raw mobility. A cannon with no useful screen anywhere on its lines is doing almost nothing, whatever it looks like. Can a cannon attack two pieces at the same time in xiangqi? Yes, if two of its lines each already have a single screen with an enemy piece beyond it. That double threat is the basis of the cannon fork. Can a cannon be used to defend the palace in xiangqi? To a limited degree. A cannon aimed down a file the enemy wants can discourage its use, but it cannot occupy palace points the way advisors and elephants do. How much stronger is a cannon battery than a single cannon? Considerably more than double, because a battery removes the single-screen dependency: the front cannon supplies the rear one's screen automatically, every move. What is the fastest way to activate a cannon in xiangqi? Move it once, onto a line that already threatens something, typically the central file. A second cannon move before other pieces develop is usually wasted time. ## Try it on a real board Reading an answer is one thing; playing it is another. Free, instant, and nothing to install.