Sequence
By Kenji Tanaka · Updated
Definition
A sequence (shuntsu) is three consecutive numbers in one suit, like 456 of bamboo. Only the numbered suits form them; honors never do. Sequences are the flexible backbone of most hands and of pinfu, sanshoku, and ittsu, completed from your own draws or by a chii from the left.
Sequence
What Sequence means
A sequence is a meld consisting of three consecutive numbered tiles of the same suit. In Japanese, it is called shuntsu (順子). Sequences are fundamental combinations in mahjong that form one of the primary ways to complete a winning hand.
Sequence in detail
A sequence must meet three specific criteria:
- Three tiles: Always exactly three tiles in length
- Consecutive numbers: The tiles must be numbered sequentially (e.g., 3-4-5, 7-8-9)
- Same suit: All three tiles must belong to the same suit (bamboo, character, or dot)
Valid sequences include combinations such as 1-2-3, 4-5-6, 7-8-9 of bamboo; 2-3-4, 5-6-7, 7-8-9 of characters; or 3-4-5, 4-5-6, 6-7-8 of dots. The sequence cannot wrap around, you cannot form a sequence with 9-1-2, as the numbering is not consecutive in the proper order.
Sequences differ from koutsu (triplets, called with pon), which are three identical tiles, and kans, which are four identical tiles. While a pon requires matching tiles, a sequence requires progression. Both are essential meld types in mahjong construction.
In the context of hand-building, sequences provide flexibility because multiple tiles can potentially complete them. For example, if you hold 3-4 of bamboo, either a 2 or a 5 of bamboo will complete the sequence. This makes sequences valuable during active play, as they offer multiple completion paths.
Sequences can be formed in two ways during gameplay:
- Concealed sequences: Sequences formed entirely from tiles you draw yourself and keep hidden in your hand; they need no call or declaration
- Melded (open) sequences: Sequences formed by calling “chii” on a tile discarded by the player to your left, combining it with two tiles from your hand; the meld is placed face up
Seeing Sequence in play
Imagine you are playing a game and your current hand contains: 3-4 of bamboo, 5-6-7 of characters, 2-2-2 of dots, and various other tiles. You already have one complete sequence (5-6-7 of characters) and the beginning of another (3-4 of bamboo). When the player to your left discards a 5 of bamboo, you may call “chii” to take that tile and complete your second sequence: 3-4-5 of bamboo. This meld is now exposed on the table.
Later, when you draw a 2 of bamboo from the wall, the sequence simply stays concealed in your hand; sequences completed by your own draws are never declared or exposed. This concealed sequence counts toward your winning hand when you eventually declare victory.
Related Terms
- Shuntsu: The Japanese term for sequence; used interchangeably in mahjong terminology
- Meld: The general category of tile combinations, which includes sequences, pons, and kans
- Chi: The call used to claim a discard from another player to complete a sequence
- Pon: A meld of three identical tiles, contrasting with the consecutive nature of a sequence
- Kan: A meld of four identical tiles, representing the largest single meld type
Understanding sequences is crucial for developing effective mahjong strategy, as they form the backbone of most winning hands and offer strategic flexibility during play.
Related Terms
Meld
面子
A meld is a completed set of three tiles: a sequence (shuntsu) of consecutive numbers in one suit, or a triplet (koutsu) of identical tiles. A kan of four also counts as a meld for hand structure. The standard winning shape is four melds plus a pair. Concealed melds, formed from your own draws, score more fu and keep closed-only yaku alive; called melds trade that value for speed.
Chi
チー
Chii claims the discard of the player on your left to complete a sequence, the only call that is position-restricted. It opens your hand, forfeiting riichi, menzen tsumo, and closed fu, so the standing advice is: no chii without a yaku plan, usually tanyao. Because only one seat can feed you, chii chances are scarcer than pon, and every one telegraphs part of your hand.