Riichi 500
Prologue
I originally created this as “Mahjong Five” just to get my family to play Mahjong with me, but over time, it evolved into a completely different ruleset, thus Riichi 500 or formally called 五五麻雀 was born. I wanted the scoring to be easy enough that you can calculate it right in your head. The game is definitely more aggressive by nature because of how the dealer bonus works, but hopefully, it still promotes building closed hands the way Riichi does.
Setup & Core Assumptions
- Starting Stack: 50,000 points per player.
- Base Rules: Standard Riichi Mahjong rules apply automatically unless explicitly stated in this guide.
- The Honba Rule: There is no difference between dealer and non-dealer scores. Instead each Honba (counter) gives a direct +1 Han bonus per counter to the dealer if they win.
- Honba Reset: When the dealer changes, the Honba count immediately resets to 0. This is to make sure that the bonus doesn’t bleed over to the next person.
Scoring
Step 1: Calculate Fu
Total Fu = Meld 1 + Meld 2 + Meld 3 + Meld 4 + Pair + Wait- Melds: +500 if triplet, +500 if quad, -500 if open.
- Pair: +500 if value pair.
- Wait: +500 if not two-sided.
In other words:
| Type | Condition | Fu Granted |
|---|---|---|
| Melds | Open Triplet | 0 |
| Melds | Closed Triplet / Open Kan | 500 |
| Melds | Closed Kan | 1000 |
| Pair | Value Pair (Dragons, Seat Wind, Prevalent Wind) | 500 |
| Pair | Any other standard pair | 0 |
| Wait | Complex (Tanki/Single, Kanchan/Inside, Penchan/Edge) | 500 |
| Wait | Ryanmen (Two-sided) | 0 |
Fu still exists mainly to preserve the identity of a closed Pinfu (0 Fu) hand. A hand with open triplet can hit 0 Fu under my system, which is admittedly weird, but making it open invalidates a closed Pinfu hand anyway. This will hopefully lessen the math while keeping the spirit of closed Pinfu alive.
Step 2: Calculate Total Han
- For Non-Dealer: Total Han = Yaku Value + Fu Milestone + Dora + Honba Bonus
- For Dealer: Total Han = Yaku Value + Fu Milestone + Dora
- The Fu Milestone: If your Total Fu reaches 1500 or more, you automatically get a +1 Han bonus!
- Honba Bonus: Honba gives a direct +1 Han bonus per counter to the winning hand. A Honba 0 adds 0 Han, Honba 1 adds 1 Han, and so on.
Step 3: Base Score to Pay Table
The base score uses this formula until Mangan. After Mangan, the Riichi multipliers apply directly to the Mangan cap.
Base Score = 500 × 2Han − 1
In other words:
| Total Han | Hand Tier | Base Score |
|---|---|---|
| 1 Han | Standard | 500 |
| 2 Han | Standard | 1,000 |
| 3 Han | Standard | 2,000 |
| 4-5 Han | Mangan | 4,000 |
| 6-7 Han | Haneman | 6,000 |
| 8-10 Han | Baiman | 8,000 |
| 11-12 Han | Sanbaiman | 12,000 |
| 13+ Han | Yakuman | 16,000 |
- Tsumo (Self-Draw): Every single non-winner pays the winner the Base Score.
- Ron (Discard): The discarder has to pay the entire non-winner payment. The discarder pays the winner their own Base Score, plus the Base Score of the other two players who didn’t win. But a Ron is not simply the Base Score multiplied by 3, for the reasons explained in the section below.
Special Scenarios
Double/Triple Ron (Multiple Winners)
Because a discarder must cover the payment of the other players, a Double/Triple Ron shifts based on how many non-winners are left to be compensated.
- Example: Let’s say you deal into both West (3 Han, 2,000 Base) and East (Mangan, 4,000 Base).
- Because West and East both won, there is only 1 remaining non-winner at the table besides you.
- To West: You pay 2,000 (your payment) + 2,000 (for the 1 other non-winner payment) = 4,000 points.
- To East: You pay 4,000 (your payment) + 4,000 (for the 1 other non-winner payment) = 8,000 points.
- Your Total Payout: 12,000 points.
Sekinin Barai (Pao Penalty)
If you feed someone the final open meld for a visible Yakuman (like Daisangen), the responsibility splits if they win via Ron:
- If the discarder is not you, that discarder only pays their own portion (16,000).
- You (the Pao player) must pay your own portion plus that of the other non-winner (16,000 + 16,000).
Exhaustive Draws & Penalties
Noten Penalty = Total Tenpai Players × 500End of Round Payouts:
- 0 Players Ready: 0 points change hands.
- 1 Player Ready: The 3 Noten players each pay 500 points to the lone Tenpai player. (Tenpai player gains +1,500).
- 2 Players Ready: The 2 Noten players each pay 1,000 points to both Tenpai players. (Tenpai players each gain +2,000).
- 3 Players Ready: The single Noten player pays 1,500 points to all three Tenpai players.
- 4 Players Ready: 0 Noten player pays 2,000 to all four Tenpai players… so no points change.
Taking a -4,500 point hit for being the lone Noten player sounds brutal, but the Han scoring mirrors the scaling of Riichi dealer scoring, which is higher. This punishing draw mechanic encourages you to consider Mawashi before deciding to completely gives up your hand.
Misconduct & End-Game
- Chombo: If you get a Chombo, you pay a flat Mangan Value to everyone (4,000 to every other player, giving you a -12,000 point loss).
- End-Game Uma: +15 / +5 / -5 / -15
Exclusive Variant Yaku
On top of the standard Riichi Yaku, I introduced 2 custom Yaku for this variant.
GoGo Riichi
Formal Name: 五五リーチ
You can do this once per match. If you are currently in last place and you declare GoGo Riichi by betting 5,000 points, your hand value is guaranteed to be a Mangan at minimum if you win.
This is inspired by “Inazuma Riichi” from Ikeda Kana effect. See Saki Card for more information.
ゴゴゴゴゴゴゴゴゴゴゴゴ
Formal Name: 吾五午後御呉語誤悟護互伍
You must build a closed, standard 4 melds + 1 pair winning hand that uses all 12 copies of the 5 tiles.
Example of legal hands:
You must say ゴゴゴゴゴゴゴゴゴゴゴゴ (gogogogogogogogogogogogo) in an ominous way before declaring Ron or Tsumo. You didn’t just win the match, you won the entire tournament! Though this probably doesn’t matter to you because you have also officially won at life.
That’s it. Thank you for reading. Any feedback is welcome!