Master the discovered attack in xiangqi, where moving a cannon's screen unveils a hidden threat. Learn discovered checks, double checks, and the flying general.
A discovered attack in xiangqi happens when you move one piece and, in doing so, unleash a second piece that was waiting behind it. The moving piece makes its own threat while a hidden attacker springs to life along the newly opened line. In Chinese chess (象棋) this idea reaches its purest form because of the cannon, a piece whose entire nature revolves around what sits on its firing line.
Discovered attacks and their most brutal cousin, the double check, win games because they attack two things at once and are almost impossible to parry. In this guide you will learn how the cannon screen creates uniquely powerful discoveries, how horses and chariots join in, how your own general becomes a discovered attacker through the flying-general rule, and why a double check can end a game on the spot.
What Makes a Discovery in Xiangqi Different
In most chess families a discovered attack simply means unblocking a line piece. Xiangqi has that too, but it adds a twist no other game has: the cannon needs exactly one screen to capture, so the pieces sitting on its line are not obstacles but ammunition. Moving a screen can turn a cannon on, turn it off, or redirect it entirely, which makes the cannon the richest discovery piece in the game.
The payoff of any discovery is the double threat. The piece you move creates one attack, and the piece you reveal creates another, and your opponent usually cannot answer both. When the revealed attack is a check, the situation becomes even sharper, because the defender must respond to the check and has no time to save the piece your moving unit is attacking.
The best discoveries are the ones where the moving piece is itself doing damage, capturing material, forking, or threatening mate, while the unveiled piece delivers the decisive blow. Learning to see both layers at once is the skill that separates tactical players from the rest.
The Cannon Discovery: Moving the Screen
Picture a cannon aimed down a file at the enemy general or chariot, with one of your own pieces sitting on that file as the screen. The moment that screen piece moves, the cannon can no longer fire, unless another piece takes its place. But flip the idea around: place your cannon so it has two pieces on the line, then move the front one. Now the cannon has exactly one screen and suddenly threatens to capture, all while the piece you moved makes its own threat.
This is the signature xiangqi discovery. A horse or soldier steps forward with a threat of its own, and behind it a cannon that now has a single screen bears down on the general. The opponent must deal with the front piece and the cannon at the same time, and often cannot. Because the mechanic is invisible to newcomers, these discoveries win countless games at the club level.
The reverse is a defensive trap to avoid: never casually move a piece that is serving as a screen protecting your own general from an enemy cannon. Uncovering a check against yourself is one of the most common blunders in the game. Always count the screens on any cannon line pointed at your palace before you move.
Horse, Chariot, and Flying-General Discoveries
The horse and chariot make more conventional discoveries. A horse or chariot standing in front of a friendly chariot can step aside with a threat, opening the file so the rear chariot checks or attacks along the newly cleared line. Because the horse can also give check from its jump, a horse that moves off a file can create a double attack: the horse threatens one piece while the unblocked chariot threatens another.
The flying-general rule gives xiangqi a discovery found nowhere else. If a single piece stands on the open file between the two generals, that piece is holding back a devastating threat, because the instant it moves, your general controls the whole file. Move that blocker with a threat of its own and you have discovered an attack by your own general, forcing the enemy general to freeze or flee.
This general-powered discovery is subtle but decisive. The blocker on the shared file is effectively pinned in place for the defender, so if it is your piece, moving it can spring a trap, and if it is the enemy piece, you can often win it because it dare not move. Always notice which pieces sit on the file between the two generals.
Double Check: The Attack You Cannot Block
A double check is a discovery where both the moving piece and the revealed piece give check at the same time. It is the most forcing move in all of xiangqi, because you cannot block two lines at once and you cannot capture two attackers with one move. The general itself must move, and if it has no legal step, the double check is mate.
In xiangqi a double check often pairs a chariot or horse with a cannon. The front piece slides or jumps to give one check while unveiling the cannon behind it, and the cannon delivers the second check over the remaining screen. Since the tiny palace gives the general so few escape points, a well-timed double check frequently ends the game immediately.
When you are hunting for a knockout, always test your discovered-attack ideas for the double-check version. Ask whether the moving piece can give check itself while it reveals the hidden attacker. If both fire at once, you may have found the cleanest finish on the board, one that no advisor, elephant, or block can answer.
Train Your Vision on XiangqiPlay
Discovered attacks reward players who see the whole board, not just the piece they are touching. Work through the tactics puzzles on XiangqiPlay and make a habit of asking, before every move, what your pieces would reveal if they stepped aside, and what your opponent might reveal against you.
Then take that double vision into live games. Setting up a cannon battery or a hidden general threat and springing it at the right moment is one of the great joys of Chinese chess, and each one you land makes the next easier to see.