List of chess terms
A key concept of positional chess. It is a move, or sequence of moves, to deal with an opponent's plan before it starts. Sometimes one can completely stop the threat; sometimes one just makes the plan relatively harmless. The idea was spelled out in detail in Nimzovich's books My system and Chess praxis. Prophylactic moves are often seen in games by Capablanca, Petrosian and Karpov.