Beacuse En Passant actually means in passing, and since when two things pass eachother they are going in opposite directions, and pawns only move forward so they pass each other going opposite directions.
Sounds wierd, but I figure it works.
Why Only Pawns in En Passant?
Sort:
Perhaps, although the intial two move is reminiscent of actual two moves of a pawn. That is one of the reasons for En Passant, taking as the pawn passes (if it did take two moves). So with the spirit of the inital 2 move in mind, why can't another piece?
"Now, why did the rule makers only allow pawns? Theorectically, if a pawn can capture En Passant, why can't a bishop, knight, queen, rook, king, etc.? "
It would be so,boring and sad chess.Chess would lose 1 big part of his beauty.
Apr 11, 2008
0
#5
If all the pieces could take en passant, it would be very difficult for the king to escape from check. If you want that rule, perhaps you would like to be able to promote pawns to additional kings.
I think there is some misunderstanding of the suggestion. themirrortwin is not suggesting that other pieces could be captured en-passant, but that other pieces can capture en-passant. So, pawns would still be the only pieces removed from the board by en-passant captures, but it could be done by a bishop, knight, etc.
A restatement of the question: When a pawn moves forward two squares, should it be vulnerable to capture on the square it skips from all the other pieces, not just pawns?
GreenLaser, I don't understand why this makes it so much harder for the king to escape check? Or does this clarification change your sentiment?
Loomis is correct and better phrased my question.
Apr 12, 2008
0
#8
Loomis, your last two sentences seem correct, although if moving a pawn two squares is the only way to block a check, in that situation, the king is less secure.
Really? Could you give an example? If that is indeed the case, then I have an answer to my question ;P
A knight only captures one square. If it wanted to capture the pawn which just moved 2 spaces, it would have to land on the sqaure behind it to capture the pawn. Just like when a pawn captures another in En Passent, it captures diagonally to the sqaure right behind the pawn which just moved 2 spaces.
Apr 13, 2008
0
#11
Here is an example using the knight: White has a king on h2 and plays a pawn to f4 to block a check by a black bishop on e5. A black knight on g5 (which with the bishop was forked) captures the pawn on f3 with a double check. The knight gives check and the bishop is still giving check, perhaps a "recovered" check.
Apr 13, 2008
0
#12
I think the most to the point answer is that only pawns are deprived of any further opportunity to capture an opposing pawn because it took advantage of the initial two square advance. Pieces can come back and make the capture later.
Those are both good reasons. I speculate that the game would still be fine if the rule was changed, but now I have excellent answers to my ponder. 
Apr 15, 2008
0
#14
If you think about it though, a pawn would not move up two squares.
i.e., for en-passant, the pawns have to be on neighbor columns so then so would the other pieces but watch
If you actually think about it, the question is kind of stuppid
Apr 15, 2008
0
#15
I think redhotman's example is a little off, because when a pawn takes via e.p., it has to have started its turn on the 4th (or 5th, for white) rank, whereas the Rook in the example is on the 3rd rank (which is why it would be an obvious capture. However, it is a useful diagram because it illustrates how pointless it would be for a Rook to be able to take a pawn e.p. (because if the Rook starts on the 4th rank, as a Pawn would if it were to take e.p., and the opposing pawn moves out 2 spaces, the rook could simply... take it). As for a Knight, the position is filled with ambiguity (which way should it capture? Where should it be able to start in order to make it a valid move? Could it ever capture 2 pieces at once, as 66_Mustang pointed out? etc...) The remaining pieces (that do not force these questions) are those that take diagonally, (the Queen, Bishop, and pawn). I don't think very many people would appreciate increasing the Queen's already broad (no pun intended) power. As for the Bishop, well, I'd say the downsides are that it would place a bishop on the 3rd (or 6th) rank after the capture, which is prone to recapture by other pawns in many cases, or as GreenLaser pointed out, it might make it easier to control the King, thus (unfairly) shifting the advantage to the attacker. So, all of the pieces having been ruled out, the Pawn is the only one for which it makes sense to give the e.p. ability. Which is the way it is now. As they say, "If it ain't broke, don't fix it."
i compare it to bumper cars -- oops missed you heading forward -- i'll just rap you in the side
basser, I think there is some misunderstanding of how ep captures from other pieces would work. Hopefully some diagrams will clear it up.
A long long time ago when the pawns could only move one square at a time, you could stop a pawn in it's tracks by controlling the square in front of the pawn. When the rules were changed to allow the pawn to move 2 squares forward the idea of controlling the square in front of the pawn became obsolete for pawns on their original square because those pawns can skip over the square in front of them. This was rectified for a pawn controlling the square in front of a pawn by the en passant rule, but not for other pieces.
Examples:
The white knight is controlling the square in front of the f7 pawn and the black bishop is controlling the square in front of the d2 pawn. But because of the rule that allows the pawn to move forward 2 squares on it's first move, these pieces are robbed of their ability to control the pawn. Instituting en passant captures for pieces would mean black could capture 1. d4 Bxd3 e.p. The en passant capture always happens on the square the pawn passed over. The knight would capture e.p after 1. ... f5 2. Nxf6. I don't see where anybody is getting ambiguity about the knight taking two pieces. The knight only takes the pawn if it lands on the square the pawn passed over and there can't be any other pieces on that square.
The reason for the en passant rule change was to compensate for another rule change - allowing pawns to move two squares on their first move. En passant ensures pawns cannot escape capture by those in an adjacent file. It doesn't allow them to permanently escape capture by any other piece.
There are still variants of chess where neither is allowed, but they are not as popular as proper chess. That would seem to justify the rule changes. Similarly i'm sure variations of the en passant rule have been tried over the centuries, including the one mentioned, but it never achieved widespread popularity. I would assume that is because it made for a poorer game.
The en passant rule was introduced in order to stop positions becoming too blocked with pawn chains and therefore fewer chances of breakthroughs resulting in too many draws.
I remember when I first learned about En Passant and I have always had a question, so I will poss the question to the forums!
Orginally, pawns could only move forward 1 space, but the rules changed to include the inital 2 space move in the 14th or 15th century. At the same time, En Passant was invented, so that a pawn could capture another which tried to run past it.
Now, why did the rule makers only allow pawns the priveledge of capturing a pawn moving 2 spaces immediately following it's move? Theorectically, if a pawn can capture En Passant, why can't a bishop, knight, queen, rook, king, etc capture a pawn immediately after it moves 2 spaces?
Please note: I am NOT asking if pieces can capture En Passent all the time. That would be just plain silly. I am asking why can't say a bishop capture a pawn that has just moved 2 spaces by moving to the square it passed through in the same way a pawn has that right.