Can a soldier defend another soldier 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
Only sideways, and only once both have crossed the river. A soldier captures exactly the way it moves, forward and, after crossing, sideways, and never diagonally. So two crossed soldiers standing next to each other on the same rank defend each other; an uncrossed soldier defends nothing, because it has no sideways attack yet.
Why this differs from chess pawns
Chess pawns defend each other diagonally, which is the basis of a pawn chain. Xiangqi soldiers cannot, since they never capture diagonally at all, so there is no equivalent structure. Soldiers spread out from the start specifically because they are not meant to lean on each other the way pawns do; see how the soldier moves for the full picture.
When mutual defence actually happens
It comes up mainly in an advanced pawn storm near the enemy palace, where two or three crossed soldiers sitting on the same rank can hold each other up against a defender trying to pick them off one at a time.
Related questions
Can an uncrossed soldier be defended by anything?
Yes, by a chariot, horse, cannon or the general, just not by another soldier standing beside it.
Is a defended soldier worth more than an undefended one?
In practice yes, since it cannot simply be picked up for free, though its nominal value does not change.
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