--- title: "Using a Piece About to Be Lost as a Cannon's Screen First ยท Xiangqi Master" description: "A piece under attack with no safe retreat can sometimes be moved onto a cannon's line as a screen instead, extracting a capture from the move that was going to lose it anyway." url: https://xiangqimaster.com/blog/how-can-a-piece-about-to-be-captured-be-used-as-a-cannons-screen-first updated: 2026-09-23 source: Xiangqi Master (https://xiangqimaster.com) license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) --- # How can a piece that's about to be captured be used as a cannon's screen first? These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing. > Direct answer > > If a piece is going to be **lost anyway**, with no safe square to retreat to, moving it onto a friendly cannon's line as a **screen** can sometimes extract real value from the loss, enabling a capture that piece's arrival makes possible, rather than simply losing it for nothing. ## Why this is a genuine desperado idea, not just a consolation A piece with no future is not really being "sacrificed" in the usual sense, it was already lost the moment it had no safe move. Using its last move to create a cannon capture, rather than retreating to a square that only delays the inevitable, converts a pure loss into a loss that also wins something back. See [the desperado piece](https://xiangqimaster.com/blog/what-is-a-desperado-piece) for the general version of this idea. ## What makes this specifically a cannon-screen case The mechanism is narrower than a general desperado capture: the doomed piece is not doing the capturing itself, it is enabling a friendly cannon to capture through it by landing exactly one square in front of the cannon's target. Recognising that a doomed piece happens to sit on a useful cannon line is the actual skill here. ## Related questions Does this work with an enemy cannon's line instead? No, moving a doomed piece onto an enemy cannon's line would simply hand the opponent the screen they need; this idea only works with your own cannon. Is this a common tactic or a rare one? Reasonably uncommon as a deliberate plan, but worth checking for whenever a piece is about to be lost with no good retreat available. ## Related xiangqi resources Cannon tactics Screens, batteries and discoveries How the cannon moves Captures only by jumping exactly one screen Xiangqi tactics Forks, pins and discovered attacks ## Try it on a real board Reading an answer is one thing; playing it is another. Free, instant, and nothing to install.