| Mahjong Variant | Value |
|---|---|
| Chinese Classical | Always |
| New Style | Always |
| Japanese Classical | Always |
| HK Old Style | Always |
| Guangdong Style | Always |
| Taiwanese | N/A |
| Chinese Official MCR | 88 "Fan" |
| Guangdong MCR | 24/36 Points |
| Japanese Riichi | Yakuman |
| Let's Mahjong! | 13 Fan |
| Zung Jung | 320 Points |
Thirteen Orphans （十三么）is an extraordinary pattern that consists of one of each terminal and honor tile. The fourteenth tile can be any other Terminal or Honor tile. All tiles must be self-drawn except for the last tile.
If the wait is on all thirteen possible tiles, the hand is pure; otherwise, the hand is impure.
An example of a Pure Thirteen Orphans. The blue tile is a 13-sided wait.
By Mahjong Variant
Hong Kong New Style (1950s)
If an opponent attempts to make a Concealed Kong, but the tile is the last one needed to complete a Thirteen Orphans, the player can rob it.
Japanese Riichi Mahjong
Thirteen Orphans is one of the three Yakuman Gosanke 「役満御三家」, a group of Yakuman known for being easier to get than the others.
If an opponent attempts to make a Concealed Kong, but the tile is the last one needed to complete a Thirteen Orphans, the player can rob it. This is the only instance where a tile from a Concealed Kong can be called.
Some groups award Double Yakuman for a Pure Thirteen Orphans.
Chinese Official MCR
Does not combine with All Types, Concealed Hand, or Single Wait. (Combines with Fully Concealed if Self-Drawn).
Guangdong MCR
An 'Impure Thirteen Orphans' is worth 24 Points, while a 'Pure Thirteen Orphans' is worth 36 Points.