Ask what your opponent wants
Prophylaxis is a move, or a series of moves, that prevents your opponent from doing something. The word comes from Greek and means roughly guarding in advance. The idea is associated with Aron Nimzowitsch, and two World Champions became known for it: Tigran Petrosian and Anatoly Karpov.
The habit is easy to describe and hard to learn: before you make your move, ask what your opponent would do if it were their turn. If the answer is dangerous, stop it first.
Prophylaxis in the opening
Many common opening moves are prophylaxis. The Najdorf Variation of the Sicilian is built on the move 5…a6, which keeps White's knight and bishop from coming to b5.
The king's safety
A common prophylactic move is luft: a pawn move like h3 or h6 in front of the castled king, so that it has a square to escape to. It prevents mate on the back rank, which you can read about among the checkmate patterns. After castling long, the king often moves one more step, to b1 or b8.
Sometimes it is too late. At Hastings in 1895, Curt von Bardeleben left his king on e8 one move too long.
What happened is on the page about the isolated queen's pawn, and the whole game is among the famous games.
Stop the plan
Prophylaxis isn't only about threats on the next move. Often it stops a plan that would only have become dangerous several moves later. In the 1985 World Championship, Garry Kasparov had a knight on d3 that paralyzed Anatoly Karpov's position. Karpov wanted his knights back in play.
Read more about the knight on d3 on the page about knight outposts.
Petrosian's way
Tigran Petrosian was strongly influenced by Nimzowitsch's idea of prophylaxis. He often put more effort into stopping his opponent's attack than into his own, and he rarely went on the attack unless he felt his own position was completely safe. A well-known move of his was both prophylaxis and an exchange sacrifice: he gave up the exchange to bring a knight to d5, where it stopped his opponent's center pawns. It is on the page about the exchange sacrifice.
Common mistakes
- Seeing only your own plans. Your opponent has a plan too, and it may be faster.
- Prophylaxis for no reason. A quiet move that prevents nothing is a lost tempo.
- Waiting too long. Like von Bardeleben: one move too late can be one move too many.
Remember
- Ask what your opponent wants before you decide on your own move.
- Stop the dangerous thing first, ideally with a move that also helps you.
- Give the king luft in time.
Frequently asked questions
What does prophylaxis mean in chess?
A move or a series of moves that prevents your opponent from doing something. The word comes from Greek and means roughly guarding in advance.
Which players are known for prophylaxis?
The idea is associated with Aron Nimzowitsch, and Tigran Petrosian and Anatoly Karpov are known for it. Attacking players such as Mikhail Tal and Garry Kasparov used it too.
What is luft in chess?
A pawn move in front of the castled king, usually h3 or h6, that gives the king a square to escape to. It prevents mate on the back rank.
Updated November 14, 2026