Riichi

What is Riichi in Japanese Mahjong?

Riichi is one of the most iconic one-han yaku in Japanese Riichi Mahjong. It involves declaring that your fully concealed hand is in one tile away from winning, then committing not to change your hand’s structure any further. Riichi is a hallmark of Japanese Mahjong, representing a pivotal turning point in a hand. By announcing Riichi, you trade flexibility for the potential of higher rewards, bonus dora, and the powerful psychological edge it exerts on your opponents. Mastering when and how to declare Riichi—and how to respond to an opponent’s Riichi—is a crucial aspect of skilled Riichi Mahjong play.

How to Achieve Riichi？

Fully Concealed Hand：Your hand must be completely closed (no open melds such as chow, pung, or open kong). Concealed kongs do not violate the “concealed” requirement, as the hand remains closed in essence.

Tenpai /Ready Hand: You must be exactly one tile away from winning. At the moment you enter Ready Hand, you can declare Riichi by placing a 1,000-point deposit on the table.

Locked Hand：After declaring Riichi, you may not alter your hand by calling discards. You also cannot change your waits by swapping tiles. You can only draw from the wall or claim a discard if it completes your winning hand.

Riichi Score Calculation

One-Han Value: Riichi itself is worth one han.

However, Riichi also grants access to potentially lucrative bonuses:

Ippatsu: If you win within the very next turn cycle (before anyone makes a call), you get an extra one han.

Ura Dora: Hidden dora indicators revealed only if the hand finishes after a Riichi declaration. They can substantially increase your hand’s fu and han.

Stacking with Other Yaku: Because the hand is fully concealed, you can also qualify for Fully Concealed Hands (if you self-draw), Pinfu, All Simples, and many other yaku if their conditions are met. Riichi can transform an otherwise modest hand into a higher-scoring one once the additional dora and possible ippatsu bonuses are factored in.

What is the Strategy and Risk of Declaring Riichi?

Risk vs. Reward: Declaring Riichi can escalate your score if you win—especially with ura dora flips. However, you lock your hand and can’t switch waits or defend by folding if you encounter dangerous discards.

Pressure Tactic: When an opponent declares Riichi, the other players often adopt more defensive strategies, discarding safer tiles and reducing risk.Conversely, declaring Riichi can intimidate opponents, sometimes causing them to discard tiles that inadvertently help you.

When to Declare Riichi: Often you’ll declare Riichi as soon as you hit Ready Hand, especially if you can wait on multiple winning tiles. Sometimes, you might delay Riichi if you can improve your wait or incorporate more dora tiles—but delaying runs the risk of losing the chance entirely.