Han

Han is the primary scoring unit in Japanese Riichi mahjong. Each yaku (named pattern) in a winning hand contributes a fixed number of han, and dora bonus tiles add further han, so a hand's total han is the sum of all its yaku plus all its dora. Han, together with fu, determines the final point value through the Riichi scoring tables.

Han accumulate from several sources. Riichi is 1 han, tanyao is 1 han, a yakuhai triplet is 1 han each, while bigger patterns like honitsu give 3 han closed (2 open) and chinitsu gives 6 han closed (5 open). Dora, akadora (red fives), and ura dora each add 1 han per matching tile but are not yaku themselves, meaning they cannot be the sole reason a hand wins; a hand still needs at least one true yaku to be valid.

The relationship between han and score is non-linear. At low han the fu value matters and the score is computed from a base-points formula, but once a hand reaches roughly 3-4 han with high fu, or 5+ han outright, it hits fixed limit tiers. Five han is a mangan, 6-7 han a haneman, 8-10 a baiman, 11-12 a sanbaiman, and 13 han a counted yakuman. This is why pushing a hand from 4 to 5 han is often a major value jump.

Han is unique to Riichi and Japanese-derived rules. Chinese Official mahjong uses fan with fixed per-pattern points, Hong Kong uses faan with exponential payouts, and Taiwanese uses tai with linear payouts, so the word han should not be mixed with those systems. For example, a closed riichi hand with tanyao, one dora, and a self-draw scores 1+1+1+1 han for 4 han total, then looks up the result against its fu.