Can the general be unable to capture an adjacent enemy piece?
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 general captures like any other piece, but a capture that would leave it in check is illegal regardless of how tempting the target looks. An enemy piece standing next to the general inside the palace, defended by something that could then take the general, is safe from capture for exactly that reason, the move is refused before it is ever considered a trade.
Why this trips players up
An undefended piece adjacent to the general is always fair game, so it is easy to assume every adjacent piece is. The moment a soldier or another piece has crept next to the general with genuine backup, the capture that looks free is not available at all, and testing legality first rather than assuming it is a habit worth building.
What the attacker actually gains from this
A defended piece parked next to the general can pin down the general's own options without ever being captured, since the general simply cannot take it. That alone can be enough to remove an escape point from a mating calculation, even if the piece itself never does anything else.
Related questions
Is this the same idea as a normal defended piece anywhere else on the board?
Yes, the general is just as bound by ordinary defence as any other piece; nothing about it being the general changes the rule.
Can the general ever be forced to capture such a piece anyway?
Only if it is the sole way to answer check, see can the general be forced to capture a defended piece.