Can a cannon ever capture a piece sitting on a point immediately next to it?
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
No, never. Capturing requires exactly one screen between the cannon and its target, which means the nearest possible point a cannon can ever capture on is two steps away along its line, one point for the screen and one beyond it for the target. A piece standing directly next to a cannon is completely safe from that cannon, no matter how the rest of the board looks.
How this sets the cannon apart
The chariot, soldier and general can capture a piece on the very next point along a line, and the advisor one on the very next point diagonally. The cannon never can: its entire capturing mechanism depends on distance, since without a screen in between there is nothing to jump.
A practical use of this fact
A piece that would be captured by an enemy chariot on a given line is sometimes completely safe from an enemy cannon on that same line, simply by sitting directly beside it with no screen available. This is a genuine, reliable way to neutralise a cannon's threat along one specific line without moving away from it at all.
Related questions
Can a cannon ever move to a point right next to an enemy piece, even if it can't capture it?
Yes, ordinary movement along a clear line has no distance restriction; the two-point minimum only applies to captures.
Does this mean adjacent squares are always safe from cannons generally?
Only from that specific cannon on that specific line, a different cannon or a different line can still threaten the same point.
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