Ikkitsuukan: Difference between revisions

Ittsuu requires three out of the four tile groups to be composed of sequences: 123, 456, and 789.  That may only leave room for one tile group of any type, such as a triplet; and so, any yaku that requires more than one triplet, including [[sanshoku doukou]], [[toitoi]], [[sanankou]], [[sankantsu]], and [[shousangen]], is deemed incompatible. [[chiitoitsu]] is likewise incompatible as it does not use [[mentsu]], and this disqualifies [[honroutou]] since honroutou requires either toitoi or chiitoi. [[Tanyao]], [[chanta]], and [[junchan]] are incompatible as the 456 group contains no terminals or honours, but the 123 and 789 groups contain terminals. Finally, Ittsuu is incompatible with [[sanshoku doujun]] and [[ryanpeikou]] as they each require at least three sequences in a way that are incompatible with the sequences used for ittsuu.