When was the cannon added to 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
With the Song-dynasty form of the game, around the 11th–12th century. That timing is consistent with when artillery became familiar in China, and it is one of the better pieces of internal evidence for dating the modern game: the cannon cannot be older than cannons.
A useful independent check
Claims that xiangqi is two or three thousand years old run into this directly. Whatever games existed under the name 象棋 in earlier periods, they cannot have included the piece that defines the modern game. That is an argument from the game's own contents rather than from documents.
The character records the transition
砲 carries the stone radical, from the engines that threw rocks; 炮 carries the fire radical, from gunpowder. Both are used for the piece, which is a small fossil of the weapon's history sitting on the board.
Related questions
Does janggi's cannon come from the same source?
Yes, and it is modified — it needs a screen to move as well as to capture, and cannot use or capture another cannon.
Is there a cannon in chess?
No. Nothing in western chess captures by jumping a screen.
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