Why do the vertical lines stop at the river on a xiangqi board?
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
Because the river is drawn as a gap between the fifth and sixth ranks, not as a row of points. The inner file lines are simply left out there so the gap reads as water. For movement it changes nothing: pieces that are allowed to cross go straight over as if the lines continued, and crossing counts as an ordinary one-point step.
No piece ever stands in the river
There are no points inside the river. Every piece stands on a rank on one side of it or the other. A chariot moving from your side's river bank to the enemy's river bank has moved exactly one point, and a soldier crossing takes one ordinary step forward.
Usually only the two outermost lines run unbroken through the river, framing the board. That is a drawing convention, not a special rule about the edge files.
What the river does in the rules
The gap is drawn because the river matters, but only to two pieces. The elephant can never cross it, which is why it is purely defensive. The soldier moves only forward until it crosses, and gains a sideways move afterwards. Chariots, horses and cannons ignore it completely. See what the river does for the full picture.
Counting ranks across it
When you count ranks, for example to read a notation move like a chariot advancing four points, the river is not a rank. Count the points: your back rank, then the second, third, fourth, fifth (your river bank), then straight across to the sixth. It helps to count on the board once or twice until the jump across the gap feels like any other step.
Related questions
Can a horse or cannon move across the river in one move?
Yes, exactly as if the lines ran straight through. The horse's leg point and the cannon's path are counted the same way on either side of the gap.
Is the river the same width as a square?
On most boards it is drawn about one square tall, so the grid keeps even spacing. Its width is purely visual.
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