How do I use an open file toward the enemy general as a tactical weapon under the flying-general rule?
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
Because the flying general rule treats two generals facing each other on an open file as if they could capture one another, clearing every piece from that file between them, or forcing your opponent to, creates a threat that must be answered immediately: something has to block the file or the position becomes illegal for the defender to allow.
Why this is a genuinely distinct tactic from a normal threat
Most threats require your own piece to actually deliver the blow. This one only requires the file to become clear, using the enemy general's own position against it. If you can force or trick your opponent into removing the last piece blocking that file, whether through a trade, a capture, or a careless move, the position becomes immediately critical without you needing to move a piece that turn.
How to actually set this up
Look for opportunities to trade off the specific piece standing between the two generals, especially if your opponent has to recapture with something that cannot easily return to block the file again. Combining this idea with an ordinary threat elsewhere, so the opponent cannot deal with both at once, is where it becomes a real weapon rather than a curiosity.
Related questions
Can I ever deliberately clear the file on my own general's side?
Only with extreme care, since the same rule applies to you; clearing your own side's blocking piece can expose your own general to the same threat.
Is this considered a beginner or advanced tactic?
It looks simple once explained but is easy for beginners to overlook entirely, since it does not resemble a normal capture-based threat.
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