Reti Opening En Passant in Chess

In the Reti Opening, “En Passant” refers to the special capture that becomes available when a pawn advances two squares and lands adjacent to an enemy pawn, allowing an immediate capture as if it moved only one square. In Reti structures, this often arises after flexible pawn moves like c4 or e4 that can provoke a two-square response from Black. The defining feature is the timing window: the en passant capture is legal only on the very next move.