Pon (call)

Pon (also called pung as a verb) is the call used to claim an opponent's discarded tile to complete a pung, a triplet of three identical tiles. You must already hold two matching tiles in hand; when the third is discarded by anyone, you may declare pon, take the tile, set the triplet face-up beside your hand, and discard. Your hand then becomes open. The call exists in essentially every mahjong variant.

Unlike chi, which can only claim from the player to your left, pon may be called on a discard from any of the three other players. This is what makes the pon call powerful for tempo: it can interrupt the normal turn order, meaning players who sit between the discarder and you are skipped, and play resumes to your right. Pon also takes priority over chi when two players want the same tile, and a ron (winning claim) outranks pon.

The strategic cost mirrors that of any open call. In Japanese riichi, ponning opens your hand and forbids riichi, removing closed yaku, so a pon is usually justified only when it builds toward a yakuhai (a dragon or valuable wind triplet) or a fast tanyao. It also tells opponents something about your hand. Calling pon on a dragon, however, is one of the most common and efficient ways to secure a guaranteed yaku quickly.

For example, if you hold White-White and any opponent discards White, you may call pon to form White-White-White, an open yakuhai triplet that by itself makes your hand valid. By contrast, ponning a triplet of 4s gives you the set but no yaku on its own, so you would still need another scoring element to be able to win.