Pawns have the most complex rules of movement: A pawn can move forward one square, if that square is unoccupied. If it has not moved yet, the pawn has the option of moving two squares forward, if both squares in front of the pawn are unoccupied. A pawn cannot move backward. When such an initial two square advance is made that puts that pawn horizontally adjacent to an opponent's pawn, the opponent's pawn can capture that pawn "en passant" as if it moved forward only one square rather than two, but only on the immediately subsequent move. Pawns are the only pieces that capture differently than they move. They can capture an enemy piece on either of the two spaces adjacent to the space in front of them (i.e., the two squares diagonally in front of them), but cannot move to these spaces if they are vacant. If a pawn advances all the way to its eighth rank, it is then promoted (converted) to a queen, rook, bishop, or knight of the same color. In practice, the pawn is almost always promoted to a queen.
Peoiek mugimendu-arau konplexuenak dituzte: peoia aurrera mugi daiteke, hurrengo laukira, lauki hori ez badago okupatuta. Oraindik mugitu ez bada, peoiak bi lauki aurrera egiteko aukera du, aurrean dituen bi laukiak ez badaude okupatuta. Peoi batek ezin du atzerantz mugitu. Lehenengo mugimenduan peoiak bi lauki aurrera egiten badu eta aurkariaren peoi baten ondoan gelditzen bada, aurkariaren peoiak peoi hori harrapa dezake aurrerantz lauki bakarra mugitu izan balitz bezala ("igarotzean harrapatzea" ), baina jarraian datorren mugimenduan soilik. Peoiak dira mugitzeko eta aurkaria harrapatzeko mugimendu ezberdinak dituzten bakarrak. Beren aurreko laukiaren albo banatan dituzten laukietako aurkariak harrapa ditzakete (beren aurrean diagonalean dauden bi laukiak), baina ezin dute lauki horietara mugitu hutsik egonez gero. Peoi bat zortzigarren ilararaino aurreratzen bada, kolore bereko erregina, dorre, alfil edo zaldun bihurtuko da (koroatzea). Praktikan, peoia erregina bihurtzen da gehienetan.