How is the janggi cannon different from the xiangqi cannon?
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
The xiangqi cannon moves like a chariot when it is not capturing and needs a screen only to capture. The janggi cannon, under the usual rules, must jump over exactly one piece whether it moves or captures, may not use another cannon as its screen, and may not capture a cannon. The two pieces share a name and a look but play very differently.
How the xiangqi cannon works
A xiangqi cannon slides any distance along a file or rank to an empty point, just like a chariot. To capture, it jumps exactly one piece, of either colour, and takes the first enemy piece beyond it. Any piece can be the screen, including the other cannon. That makes it mobile from move one and dangerous even in the opening.
How the janggi cannon works
The janggi cannon has no ordinary sliding move. Every move is a jump over exactly one piece, landing on an empty point or capturing. It cannot jump over a cannon, and it cannot capture a cannon. So a janggi cannon with no suitable piece in front of it simply cannot move, and positions where cannons stare at each other have their own logic. Inside the palace it can also jump along the palace diagonals when a piece stands on the centre point.
What it changes in play
In xiangqi, cannons are aggressive opening pieces: the Central Cannon attacks from move one. In janggi, cannons depend on the pieces around them for mobility, so players manoeuvre to give their cannons screens and deny screens to the opponent's. A xiangqi player moving to janggi must unlearn the reflex of sliding the cannon freely; a janggi player moving to xiangqi must remember that a cannon can now move without a screen. See xiangqi versus janggi for the other pieces.
Related questions
Is the janggi cannon weaker?
It is less mobile, but values depend on the whole game's rules, so direct comparisons across the two games are not very meaningful.
Do both games have the cannon from the start?
Yes. Each side starts with two cannons in both games.
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