Double Riichi

Declared on a closed tenpai hand by discarding sideways and betting 1000 points. Locks the hand and unlocks a chance for ippatsu and uradora.

Winning within one go-around after declaring riichi, before any call or kan interrupts the turn. Closed-only by virtue of requiring riichi, and one of the cheapest ways to add a free han to a riichi hand — it stacks freely with everything else riichi unlocks.

A closed hand of all sequences, with a non-yakuhai pair and a two-sided (ryanmen) wait. Adds zero fu beyond the base — pinfu tsumo stays at 20 fu, pinfu ron rounds to 30. The high-frequency partner of riichi and tanyao in closed-attack templates.

Winning by self-draw on a fully closed hand (no calls). The default kicker on any closed tsumo win, which is why riichi + pinfu + tsumo is the canonical fast-cheap closed-attack template.

A hand containing no terminals (1s, 9s) and no honor tiles — only 2-8 of suits. 1 han, open or closed under modern kuitan rules; strict rulesets still require menzen. The workhorse open yaku, easy to lock in whenever the early hand is heavy on middle tiles.