Expert: Louis Lima - 1/13/2007

Question
what does it mean and when is it done

Answer
Hello there,

I remember how confusing the en passant rule felt when I first began to learn how to play the game. It's just such an odd move.

Here is how it works:

1. Let's supposed that you have the White pieces. At the start of a chess game your eight pawns are all lined up on the 2nd rank.

2. Now, let's supposed that in the course of the game your e pawn has reached fifth rank (e5).  The e pawn is that pawn in front of your King. If your e pawn is on the 5th rank (e5), that means it has advanced three squares forward from the starting position (e2).

3. Now, let's say your opponent, who has the black pieces, moves his d pawn two squares forward (d7-d5), right next to your e pawn.

4. Now it is your move, and at that very moment you can choose to take the d pawn via the en passant rule.

5. The way you actually capture the d pawn is by placing your e pawn on d6, and removing the d5 pawn

6. If you decide to take the pawn "en passant" you must do so at that very moment (the moment when your opponent decided to to push his pawn forward two squares right next to your pawn). If you make a different move, you cannot capture en passant any more. If his pawn was on d6, instead of on d7, and just pushed it one square right next to your e5 pawn, then you cannot capture en passant.

I gave you an example using the White pawn on e5, but the rule applies to all pawns on the fifth rank (the a, b, c, d, e, f, g or h pawn).

Chess corner has a nice explanation as well, this one with graphics, which should help you visualize it better.

http://www.chesscorner.com/tutorial/basic/passant/passant.htm

I hope this helps. If not, let me know and I'll try to explain it better.  

Warmly,
Louis Lima