why only pawns can capture en-passant?

The idea behind en-passant capture is " enemy pawn could have captured it had the pawn moved only one square forward. (The capturing pawn must be on its fifth rank prior to executing this maneuver.) The opponent captures the just-moved pawn "as it passes" through the first square" Illustration:

but what if there was a bishop on a3-f8 diagonal? Illustration:

but bishop too could have captured had the pawn moved one square only. any piece could have been in that situation:

all of them could have captured had the pawn moved one square only but why only pawn is allowed to capture? IT may seem unimportant but it may be important during the game

had bishop been given right to capture en-passant, he could have captured the pawn and white would have had drawing chances. White still might have a drawing chances but it required an error from black or accurate play from White. had bishop been given right to capture en-passant, even amateurs could have drew the game.

in the following position, can you imagine black could have promoted had the bishop been given en-passat right? I thinkit would be very had for black to promote

hmm, good arguement for assigning it to pawns only. it makes sense, but I still think other pieces too should be given this privilege. why? at least, it will stop someone from wasting a move. in order to capture the pawn in the above positions, white has to waste at least a move.  if the attacking piece is knight, it will require more than a move.

what if the knight is in a position in which it can capture en passant when the knight is in endgame vs a pawn with/wihtout pawn. by en passant right, knight could have easily saved the draw

That would completely change the game of chess and in my opinion, make it worse.

also the diagrams have no moves.

why does tennis go 15 then 30 then 45? no wait, it's 40. but worse. why when tied on 40 each is it deuce? no wait again, that's the second time and thereafter once we reach 40 40. or should that be 45 45? and what happened to 3 3? I dunno. rules yano.

Just wait until Time Machines are invented. Then we will need to introduce a temporal version of the en-passent rule: capturing a Pawn as soon as the player has formed the intention of moving it, but before it actually moves.

En passant usually rewards the player who is ahead already, and usually later in the game (though occasionally it makes an entrance early when I'm playing lower rated players) in my limited experience.  Adding en passant to longer range pieces would give them too much power in the early game, allowing pawn structure to be broken much more quickly.  As it stands, en passant is further restricted in that you must make the decision immediately, making it one of only two moves I know (the other being castling) which is restricted by an artificially introduced rule of prior move status (dynamic aspect of position, I think I've seen it referred to).  In short, it's a bit arbitrary, but I can see the reasoning that would have led the inventors of the rule to create it.

it sounds good. it may be argued for the good of the game.

in a position like this bishop not being given en passant is somehow for the good of the game. had bishop been given the right, then it would be harder for white to play his B pawn.

but look at my posts above, I think at least after a while, say X moves, it should be allowed for other pieces as well I guess.

 It's not really an arbitrary rule. Pawns, historically, could only move one square. When the initial two-square move option was adopted, en passant was developed. There is more behind the rest of the rationale but I don't recall the specifcs with any accuracy. 

Also, requiring the option to be taken immediately makes it much more obvious when playing, when it can be done. Otherwise if you have a number of pawns in that position, you would have to recall if a particular pawn moved once, twice, or if the pawn on its fifth rank moved into position after the opponent's pawn was already on their fourth.  Sure notation could provide that answer but it is easier to only allow it immediately. 

Actually Bronstein suggested something like this if I'm not wrong. He was crazy.

Pretty Interesting Question

Once upon a time there was a very speedy pawn, much faster than all his fellow pawns. He was impatient and wanted to get to the eighth rank as soon as possible where a royal gown and a tiara were waiting for him. He remained, however still only on the second rank with his aspirations of queenly garb and new powers still only a distant dream. This impatient, nay importunate cove on his first move decided to race ahead two squares instead of one, by-passing a square on which he could have been captured by an enemy pawn on his fourth rank on an adjacent file. "Woah, woah! Hold on dude!" cried the enemy pawn. "Slow down! You're supposed to give me a chance to capture you on your third rank." Caissa, the Goddess of Chess, looked down on the two of them and said that the enemy pawn was quite right, that the enemy pawn did indeed have the right to capture the speedy pawn as he whizzed by, and the en passant rule thus came into being. As a concession to the wishes of the now departed speedy pawn, his confreres were now allowed to move two squares instead of one on their first move but they still had to run the gauntlet of enemy pawns that might have captured them had they only been allowed to move once on their first move. Sadly the original speedy pawn, captured because of Caissa's intervention and this new rule, never got to wear his regal gown or tiara,  though he did get to chess heaven where he got to be fondled and made part of an unsound sacrificial combination by Mikhail Tal in the latter's much celebrated celestial match with Bobby Fischer.

I don't even understand. In every single diagram you posted, you can catch the pawn with the pieces.

candidate 35 post , explains it brilliantly , the pawn is the only piece denied stopping a attacker to the rear , until en passent allowed it to go

"OI WHERE DO YOU THINK YOURE GOING PAL !"

I was thinking this during a loss recently. "I wish my queen could en passant"

though he did get to chess heaven where he got to be fondled and made part of an unsound sacrificial combination by Mikhail Tal in the latter's much celebrated celestial match with Bobby Fischer.

by karpark , soz karpark i tend to be anti copy paste anothers post but this bit was brilliant if untrue Tal would whoop Fischer lol