Fu

Fu 「符」 (pronounced as foo) is a component of scoring. It takes the hand composition into consideration in terms of tile groups, wait patterns and/or win method. In addition, every hand begins with a default start value of 20 fu. To determine the final number of fu, the sources of fu are added up along with the base number and then rounded up to the nearest 10. One exception falls on the chii toitsu yaku, which is set to 25 fu by default.

Tile groups

For shuntsu (sequences), the fu count is 0. For koutsu (triplet) and kantsu (four-of-a-kind), the fu value depends on whether they are tanyaohai (simples) or jihai/routouhai (honor/terminals).

English	Romaji	Simples	Honor/Terminal
Open triplet	Minkou	2 fu	4 fu
Open kan	Minkan	8 fu	16 fu
Closed triplet	Ankou	4 fu	8 fu
Closed kan	Ankan	16 fu	32 fu

Waits

The different basic wait patterns count for fu as well. Other wait patterns not listed include nobetan and ryanmenten. Nobetan counts for a tanki; and ryanmenten counts for ryanmen. Other combination patterns factor fu the same as the basic patterns listed here. However, the fu counts only one time. For example, a combination of tanki and kanchan only generates 2 fu from one pattern but not for both.

As for shanpon, the fu generated with this pattern rests on the tile groupings themselves as indicated in the above table.

English	Romaji	Fu value
Open wait	Ryanmen	0 fu
Closed wait	Kanchan	2 fu
Edge wait	Penchan	2 fu
Pair wait	Tanki	2 fu

Winning condition

Winning with a closed hand by ron, the hand is awarded 10 fu. These 10 fu are called menzen-kafu and do not count against the player for achieving pinfu.
A win by tsumo with an open or closed hand is worth 2 fu.
An exception to the fu for tsumo is a closed hand that satisfies all other criteria for pinfu. Such a hand does not score 2 fu for tsumo and instead gains the han for pinfu.
An open hand won by ron without any fu from koutsu or the waiting pattern gains 2 fu. This makes all open hands ineligible for pinfu.