Ryantan and pentan
Ryantan 「リャンタン」 and pentan 「ペンタン」 are combination waits, which involve a triplet and an adjacently appended numbered tile. The tile combinations for both appear identical. However, pentan involves terminals, where as ryantan does not.
| Kanji |
リャンタン ペンタン |
|---|---|
| Fu | Dependent |
| Tile types waiting | 3 or 2 sided wait |
| Tiles available | 11 tiles |
| Pattern example |
    |
Ryantan is a combination of ryanmen and tanki. It involves a triplet from 2-8 and an adjacent tile that is also from 2-8. The terminals are excluded for this combination. For example, with a 2223 ryantan, the wait can be seen as either a pair and ryanmen (22 + 23), or a triplet and tanki (222 + 3), for a wait of 1-4 and 3.
Pentan is a combination of penchan and tanki. The converse of ryantan, it can occur in two ways. The triplet can be composed of terminals, or the adjacent tile can be a terminal.
In order to reach tenpai with ryantan or pentan, no other pairs must be in your hand. In other words, these should be considered as waits to complete the pair. If you already have a "stable" pair (i.e. a pair that cannot be used for other shapes), these patterns should be seen as a triplet and an extra floating tile.
Pattern
Ryantan
Waiting for: , 
,
Note: this hand will score pinfu if won on or . If won on the , the hand will have a triplet, thus invalidating the yaku.
Pentan
Waiting for: , 
Waiting for: 
,
Tatsumaki
Tatsumaki can be viewed as two ryantan waits fused together. It consists of two triplets that are 2 ranks apart, and one floating tile between the triplets.
Waiting for: 
Note: when this pattern wins on either triplet tile (in this example, or ), the hand can complete a shanpon wait instead of a ryanmen wait. This can be important as the shanpon wait gives more fu, and possibly gives sanankou.