Can a soldier move backwards 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
No, never. Before crossing the river a soldier moves one point forward only. After crossing it may also move sideways, one point at a time — but it can never go back, in either half of the board. Every soldier move is permanent.
Crossing roughly doubles its value
An uncrossed soldier is worth about 1; a crossed one about 2, because sideways movement makes it able to attack more than the one point in front of it. Three crossed soldiers are a serious attacking force; the same three at home are almost nothing.
There is no promotion
A soldier reaching the far rank gains nothing further. It already gained everything it will ever gain when it crossed the river. On the last rank it can only move sideways, and a soldier stuck in a corner there is effectively dead.
That is worth planning around: push soldiers toward the palace, not toward the edge.
Related questions
Do soldiers capture differently from how they move?
No. Unlike the chess pawn, a soldier captures exactly the way it moves — straight ahead, or sideways once across the river.
Can a soldier move two points on its first move?
No. There is no double first step, and therefore no en passant.