Can you block a check by capturing a piece sitting on the blocking square?
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
Yes. The rules only care that the check is resolved: your general is no longer attacked once the move is made. Whether the piece that lands on the blocking point got there by moving to an empty square or by capturing something already standing there makes no difference. A capture that happens to land on the right point blocks the check exactly as well as any other move there would.
Why this comes up
It is easy to think of "block" and "capture" as two separate categories of escaping check, and to search for them one after another. In reality a single move can do both jobs at once, and overlooking that can cost time calculating a reply that already existed in a simpler form.
What still has to be true
The usual conditions still apply: the piece making the capture has to be able to legally reach that square in the first place, following its own movement rules, and the resulting position must not leave your general in check from something else. A capture that satisfies both is a completely ordinary way to answer check.
Related questions
Does this work against a horse check the same way?
No. A horse's check cannot be blocked on the line at all, because there is no line, only the leg point matters, and capturing something unrelated to that leg does not help.
Is this any different from a normal capture that answers check?
Not really; it is simply a capture that happens to land on a square that would also have worked as an empty-square block.
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