A countermove is an action taken in response to someone else's move, designed to defend against it or turn the situation to your advantage. In chess, when your opponent moves their queen to threaten your rook, your countermove might be to move your bishop into a position that protects the rook while also threatening their knight.

The word appears most often in games and competitive situations, but it works anywhere strategy matters. If a basketball team changes their defense to stop your best scorer, your coach might design a countermove like setting screens to free that player up. In a debate, when someone makes a strong argument against your position, your countermove is the response that addresses their point while strengthening your own case.

Notice that a countermove is a strategic response that considers what your opponent was trying to accomplish. If someone builds a sandcastle wall to block your path on the beach, simply complaining doesn't qualify. Building a bridge over the wall or digging a tunnel under it would be a countermove. The best countermoves do more than cancel out what the other person did: they shift the advantage back to you.