En passant: the pawn capture that lasts one move

En passant is a special pawn capture. When an enemy pawn advances two squares from its starting square and lands beside your pawn, your pawn may capture it as though it had advanced only one square. You must do so immediately on the next move or lose that opportunity.

Follow one concrete example

Put a white pawn on e5. Black plays …d7-d5. White may answer exd6 en passant: the white pawn lands on d6, and the black pawn is removed from d5. The destination square was empty, which is what makes this capture look unusual.

If Black had moved from d6 to d5 instead, en passant would not be available. If White makes a different move after …d7-d5, White cannot take en passant on a later turn.

Check the exposed lines

Like every move, en passant must leave your king safe. Two pawns disappear from their old rank during the capture. That can uncover a rook’s attack along the rank, or open a bishop’s diagonal. The special capture rule never overrides the prohibition on exposing your own king.

Connect the rule to pawn structure

A two-square pawn advance tries to gain space quickly. En passant stops it from simply bypassing an opposing pawn’s immediate capture opportunity. Strategically, the choice may open a file, change a pawn chain, or give away a useful central pawn. Availability alone does not make the capture best.

When you explain the move, name the resulting structure: which file opens, which pawn becomes isolated, and which piece benefits.

Physically remove both old pawns before judging safety

In the diagram, imagine the white b5 pawn moving to c6 and the black c5 pawn disappearing. The squares b5 and c5 both become empty. Follow the fifth rank from the rook on h5 to the king on a5: the entire line is now clear. The capture is therefore illegal.

Leaving the captured pawn on c5 in your mental picture would hide the rook’s attack. This is a visualization error, not a difficult exception. Practise updating three squares: the pawn’s origin becomes empty, its destination becomes occupied, and the bypassed pawn’s square becomes empty.

Decide whether you want the new structure

Return to the ordinary example of a white pawn on e5 and a black pawn arriving on d5. Before exd6, White’s pawn restricts Black’s pieces by controlling d6 and f6. After the capture, the white pawn controls c7 and e7 instead. White may gain a pawn, open a line, or create an advanced target that Black can soon capture.

Ask which pieces use the newly opened e-file and whether the pawn on d6 can be supported. If Black can recapture on d6, identify what recaptures: a pawn changes the structure differently from a bishop or knight. En passant is optional, so compare taking with keeping the central pawn on e5. The rule creates a candidate; the position supplies the reason to choose it.