In chess, prophylaxis (meaning ‘guarding or preventing beforehand’) is a measure taken for the prevention of a situation.
It is a move that stops the opponent from taking action in a certain area. Prophylactic moves are aimed at not just improving one’s position, but preventing the opponent from improving their own. In short, a prophylactic move is the kind that deals with stopping your opponent’s plan before it starts to become a real threat.
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