Can a cannon be blocked in xiangqi?
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
Yes, and in two opposite ways. To stop it moving, put any piece on its clear line, exactly as against a chariot. To stop it capturing, either add a second piece to the line — one screen is required, two is too many — or remove the screen it is using.
The defence people miss
Removing the screen. Everyone thinks about blocking and capturing; far fewer think about the piece in the middle. If an enemy cannon threatens you across a screen, look at the screen first — moving it away is often the cheapest answer on the board, and it is frequently one of your own pieces.
Blocking with your own general
In bare endgames the general is a legitimate blocker and screen-remover. It is safe once nothing can attack it, and a general stepping onto a line to become a second screen can switch off a cannon's check entirely.
Related questions
Does adding a piece ever help the cannon?
Yes — if the line was empty, your new piece becomes the screen and switches the cannon on. Count before you interpose.
Can I block a cannon's check?
Only by making the screen count wrong. A normal block on a clear line stops movement, not a capture that needs one screen.
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