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 for movement, checkmate and both repetition rulings: a side that forces a repetition by perpetual check or perpetual chase loses rather than drawing. The chase half has not been validated against the official casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it before publishing.
Direct answer
The generals can never face each other: a move that would leave them on an open file is illegal, so clearing the file is no threat in itself. The weapon is what the flying general rule does to a lone piece between them. It may not leave the file, so an enemy piece there is pinned. If it is yours and stands next to the enemy general, that general cannot capture it: the generals would then face each other.
Why this is a genuinely distinct tactic from a normal threat
Most defenders rely on their general to capture an attacker that comes next to it. On a file the two generals share, that answer can disappear: when your piece is the only one between them, taking it would leave the generals facing each other, so your own general, however far away, is in effect defending it. A soldier or chariot standing right in front of the enemy general can be the base of a mate for exactly this reason.
How to actually set this up
Look for files where the generals line up with only one or two pieces between them. Trading off one of two blockers leaves the other alone and pinned to the file; a horse, elephant or advisor left there cannot move at all. Combining this 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 the same thing happen on my own general's side?
Yes, the rule applies to both sides equally. If one of your pieces is the last one between the generals, it is the one pinned, and moving it off the file is illegal.
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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