en passant

in the explanation on this site, the example provided has the captured making a two square (the pawn's inital move) move prior to being captured. I want to clarify - it is not only when a pawn makes a two square move to avoid capture that en passant may be used? i.e. a one square move still qualifies?

how would it work with a one square move? Then the pawn would be on the capture square and it would proceed as a normal capture

Originally posted by impatient
in the explanation on this site, the example provided has the captured making a two square (the pawn's inital move) move prior to being captured. I want to clarify - it is not only when a pawn makes a two square move to avoid capture that en passant may be used? i.e. a one square move still qualifies?

No, en passent only applies to pawns that move two spaces.

It seems to me that the en passant rule exists so that one can not use the two-space first move as a way to slip a pawn past an opponent's without the opponent at least having the option of capture.

Originally posted by smomofo
It seems to me that the en passant rule exists so that one can not use the two-space first move as a way to slip a pawn past an opponent's without the opponent at least having the option of capture.

Yes,this is the intention. When chess was invented the Pawns could only move one square on any move. When the double square option was introduced for any Pawn's first move, it was done simply to speed up the early part of the game, and it was decided that the chance for the opponent to make a capture as if the Pawn had only moved one square should be available. This is also why the e.p. capture must be made immediately, as obviously the endangered Pawn could have moved to it's fourth rank if not captured at once.

Originally posted by smomofo
It seems to me that the en passant rule exists so that one can not use the two-space first move as a way to slip a pawn past an opponent's without the opponent at least having the option of capture.

EXACTLY !! Known since the 1500's and practiced everywhere except Italy, it became a universal chess rule in 1880.

So i wonder why only a pawn can capture another pawn using the en passant rule. Why not a bishop? If the rule's intention is so that a pawn can not be advanced 2 spaces to avoid capture from another pawn, why can it be used as a way to avoid capture from other pieces?