Can a cannon move along ranks as well as files?
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, in all four straight directions. A cannon is not restricted to its starting file; it moves along any rank or file, forward, backward, or sideways, the same as a chariot when no capture is involved. The screen requirement only applies to capturing, not to ordinary movement in any direction.
Repositioning across ranks
Shifting a cannon sideways along its rank to a new file is a completely normal and common manoeuvre, used to line it up behind a different screen or aim it at a different target than the one it started pointed toward. It costs a tempo like any move, but there is no rule limiting which direction it can travel.
Why beginners sometimes think otherwise
Diagrams of the cannon's power often show it firing straight down its starting file, which can create the impression that its whole threat lives there. In reality every rank and file it can reach works identically, both for plain movement and, once a screen is present, for capturing.
Related questions
Can a cannon switch from attacking down a file to attacking along a rank in one move?
No single move does both; it moves along one line at a time, exactly like a chariot's individual move.
Does the screen rule change on a rank versus a file?
No, it's identical in every direction: exactly one piece between the cannon and its target to capture.
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