En Passant...

How important is the "En Passant?" I recently discovered this new move from a game I played here. However the move itself played no purpose other than to show that my opposition knows the "En Passant". I was wondering if anyone had a game they could share where the "En Passant" was an influential move or even a game winner. 

I went through my archive and it looks like there's one en passant capture in about every ten games. It is a rather subtle move, and it usually never is game-breaking, since your opponent should be aware of this rule anyway. It certainly should not be used at every opportunity, since it often isn't the best move. It can only have a decisive impact when your opponent isn't aware of it, like in the following game:

That was a great set of moves. That En Passant seemed to have won you the game... But did you have another way of defeating this opponent? Do you reckon there's a game where the En Passant is the only way to win? :) That'll be pretty funny. 

Where did the En Passant come from anyway and where is the idea in taking the piece diagonally when its horizontally next to you come from...? 

I think the idea behind the en passant rule goes something like this: In early chess, pawns were only allowed to move forward one square per move (not two squares on their first move, as in modern chess). This meant that a pawn could never "get past" an opponent's pawn on a neighbouring file without allowing the opponent's pawn an opportunity to capture - a principle that had some strategic significance. For example, if White had a pawn on e5, a Black pawn on d7 couldn't advance except by d7-d6, allowing the White pawn an opportunity to capture. 

At some point, the rule that a pawn could move forward two squares on its first move was introduced. But by itself, this rule would mean that now a pawn COULD "get past" an opponent's pawn - e.g. if White had a pawn on e5, Black could play d7-d5 without allowing the White e-pawn an opportunity to capture.

So to avoid changing the strategic fabric of the game in this significant way, the "en passant" rule was introduced to "compensate" for the "pawn can move two squares initially" rule. Under this rule, if White's pawn is on e5 and Black plays d7-d5, White is allowed to capture the d-pawn "as if" Black had only played d7-d6 (which would have been Black's only way to advance the d-pawn under the old rules), and so once again Black pawn can't "get past" the White pawn.

Make sense?

The way I understand it, 150 -200 years ago pawns could only move one square at a time,even on the first move. When the rule was changed to where the pawns could move 2 squares on the first move, it eliminated the possibility of a pawn on the 5th rank taking an enemy pawn on the fourth. The ruling was made so that the pawn that was just passed could take the opposing pawn as if it had just moved one square on the next move. I hop that answers your question.I had a game once(unfortunately I don't have it anymore) where my opponent moved his pawn 2 squares to block a check. I took en passant and mate.

Ahhh that makes total sense. I never knew the rules of chess were changed. Thanks for that insight :)

you're welcome.

All of the above is true, "en passent" means "in passing" in French, so when a pawn makes a 2-square move and passes the capturing square of your pawn and stands next to your own pawn on the same rank you may capture it. This can only happen when a black pawn moves from the 7th to the 5th rank in 1 move, and white captures onto the 6th rank, or when white moves from the 2nd to the 4th rank in 1 move, and black captures onto the 3rd rank.

Here is a gem (from 1928) with en-passant giving checkmate.   

http://www.chessgames.com/perl/chessgame?gid=1242924

Wow the latest one is an awesome game ender ! I reccomend everyone to watch it!

Here's a question I would be interested to know the answer to.

I move my pawn from e2 to e4, so that it is next to your pawn which is on d4. Normally this would enable you to capture it en passant. However, you cannot, because my pawn move discovered a check from my rook on a2 against your king on h2. So you have to move your king out of check. I then move my rook somewhere. Are you allowed to then capture the pawn en-passant?

In other words, it the en-passant available for one move, or one opportunity?

No.

It has to be the very next move.