Can you explain the concept of en passant?

Question

What is en passant and how does it work? Why is it a thing?

Answer 1

En passant is a unique kind of pawn capture that can only happen right after a pawn double moves from its starting square, advancing two squares forward.

This is how it operates: Assume that a black pawn is on the opening square, e7. They advance this piece two squares to e5 on Black's turn. So the e5 pawn is currently adjacent to the white pawn on d5. In the following White turn, they can choose to capture the e5 pawn as if it had only moved one square. White must do this on the immediate next turn or the right to capture en passant is lost.

En passant is the French term meaning "in passing."

Without en passant, a pawn could move past an opponent's pawn on its first move without the risk of being captured. En passant maintains the ability for pawns to threaten each other as they advance. Hope that helps!

Answer 2

The term "en passant," comes from the French "in passing." All pawns and only pawns have this ability, and it can only be performed against other pawns in order to capture them. The reason this rule exists is to stop players from completely locking up the board with pawns. You should make sure this reasoning becomes clearer to you as you come to understand how it works. This will form a more complete grasp on the game of chess. Just consider for a moment that it means something to "lock up," the board; so much so that a rule exists to prevent it under certain circumstances. Learning the whys along with the history of the game will ensure that you end up with a broader knowledge, which enhances your overall potential.

In order for one side to perform en passant, it requires that the capturing pawn be on the 5th rank for White or the 4th rank for Black. For example, if White has a pawn on the 5th rank and Black attempts to move one of their pawns from it's starting square, two squares forward so that it is adjacent to White's pawn, then White has the option to capture Black's pawn as if it had only moved forward one square. This is why it's called "in passing," as one pawn attempts to pass by the other, yet it can still be captured, in passing.

One last way of thinking about it: we don't want our ability to choose whether to move a pawn one or two squares on it's first move to cause a situation where pawns are getting passed one another without there ever being an opportunity for a capture to occur.