Historically, pawns could only move one square. En Passant was introduced when the option was given to move the pawn two squares on the initial move. So, after that rule change, a pawn on its fifth rank, is given the option to treat a pawn that has moved two squares on an adjacent file, as if it had only moved one, if done on the next ply.
That helps prevent a player from trying to lock-up the position and logically follows from the previous rule of moving only one square. It wouldn't make sense to allow a pawn to move up one and capture on the diagonal also in the same move in your suggestion.
Hi there,
So my son and I are getting started with chess this year and we've discovered the "En Passant" move which is shocking, haha. But my question is this, as i understand it you can capture on the "double-step" move, which makes me wonder why you can't just capture your attacker as part of your double-step when you move your pawn, thus defeating the En passant move?
thanks!
Dora