1,752 puzzles in the app
A double check is exactly what it sounds like: the king is attacked by two pieces at the same time. It almost always arises from a discovered check, where the front piece moves away and gives check itself while also unmasking a check from the piece behind it.
What makes double check special is the defense, or rather the lack of one. You cannot block two lines with one piece, and you cannot capture two attackers with one move. The only legal reply is to move the king. If the king has nowhere safe to go, it is checkmate, even when other defenders could capture both attackers.
Why it is so forcing
Against a normal check, a defender has three options: capture the attacker, block the line or move the king. Double check removes the first two. That makes it the most forcing move in chess, and puzzle composers love it because it leaves the defender almost no choices.
This also explains a surprising feature of double-check combinations: you are allowed to put pieces on squares where they could be captured. As long as the king must move, the opponent has no time to take them.
A clear example
White has a rook on e1 and a bishop on e4. The black king is on e8, and the squares in between, plus f5 and f7, are empty. The rook is blocked by its own bishop.
White plays Bg6+. The bishop leaves the e-file, so the rook now checks along it, and from g6 the bishop also checks the king along the diagonal through f7. That is double check. Black cannot take the bishop and cannot block either line. The king must move, and if its own pieces box it in, the game is over on the spot.
Spotting double check in a puzzle
Look for these signs:
- One of your pieces stands between your rook, bishop or queen and the enemy king.
- That front piece can reach a square from which it also gives check.
- The enemy king has few free squares, often because its own pieces surround it.
- A check by a single piece would be easy to block or capture, but a double check would not.
Knights are excellent front pieces here, because a knight check can never be blocked. Combine a knight check with a rook or bishop check from behind, and the defender is left with king moves only.
Mistakes to watch for
- Missing it because the piece looks undefended. Players reject a move like Bg6+ because the bishop can be taken. In a double check it cannot.
- Forgetting the king’s escape squares. Double check forces a king move, but if the king has a safe square, the attack may fizzle. Count those squares first.
- Choosing a single check instead. When both a discovered check and a double check are available, the double check is usually stronger. Compare them before you play.
Practical tips
- Hunt for the double first. Whenever you have a discovered check, ask whether the front piece can check too.
- Ignore hanging pieces in the calculation. Only king moves matter after a double check, so calculate just those.
- Sacrifice to set it up. A sacrifice that drags the king onto the right line often prepares a double check one move later.
Double checks are rare in casual games, which makes them easy to miss and devastating when they hit.
