Chankan
Chankan (搶槓) is a standard yaku. It is dependent on the usage of kan, where a player may declare ron while a player calls to upgrade a minkou to a shominkan. In other words, if a player is tenpai for a tile used for an "added kan", then the player may declare a win on that tile. In most cases you are not allowed to call ron on an ankan. The exception to this is when you are in kokushi tenpai and another player's ankan is your wait.
| Type | Yaku |
|---|---|
| Kanji | 搶槓 |
| English | Robbing a kan |
| Value | 1 han |
| Speed | Varies |
| Difficulty | Very hard |