What is the weakest piece 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
By mobility, the advisor: five reachable points, never leaving the palace, unable to attack anything ever. An uncrossed soldier is the weakest by material value at about 1. But the advisor is the clearest case of a piece whose value has nothing to do with its mobility — in the endgame it decides games.
Why the advisor beats its own numbers
It fills a palace point, which removes a mating square, and it is the screen a cannon needs. Cannon-and-advisor beats a bare general; a cannon alone cannot even give check. Two advisors hold endgames that one advisor loses.
Trading an advisor for a soldier is usually a bad deal in the endgame, whatever the nominal values say.
The genuinely weak piece
An uncrossed soldier on an outside file. It is worth about 1, it cannot retreat, and if it advances to the last rank in a corner it can only shuffle sideways for the rest of the game. Those are the soldiers to trade or ignore.
Related questions
Is the elephant weak too?
Defensively no — a defended pair is very hard to break. Offensively it is worthless, because it cannot cross the river.
Should I trade advisors?
Usually not if you expect to be defending. Keep both if you can.
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