# Mahjong by Bossrod — Complete Technical & Rules Reference (LLMs Full Context) Website: https://mahjong.bossrod.com/ Canonical Guide: https://mahjong.bossrod.com/how-to-play Platform Type: Authentic 4-Player Real-Time Tabletop Mahjong Browser Game License: Free-to-play, non-gambling social game. --- ## Table of Contents 1. Overview & Core Philosophy 2. Game Equipment & The 144 Tiles 3. Turn Structure & Flow of Play 4. Melds (Chow, Pong, Kong, and The Eye) 5. Regional Rule Variants - 5.1 Filipino / Visayan Mahjong (16-Tile) - 5.2 Hong Kong / Cantonese Mahjong (13-Tile) - 5.3 Chinese Official / MCR Mahjong (13-Tile) - 5.4 Japanese Riichi Mahjong (13-Tile) 6. Multiplayer Features & Bot AI 7. Frequently Asked Questions 8. Safety, Fair Play, and Legal Disclaimers --- ## 1. Overview & Core Philosophy Mahjong by Bossrod is built to deliver authentic, multiplayer 4-player tabletop Mahjong in standard modern web browsers on mobile, tablet, and desktop without requiring native app installations. CRITICAL DISTINCTION: This is NOT Mahjong Solitaire (the single-player Shanghai tile-matching puzzle popular on PC). This is the traditional 4-player rummy-like strategy board game developed in 19th-century China and played worldwide in numerous regional styles. --- ## 2. Game Equipment & The 144 Tiles A standard Mahjong set comprises 144 tiles divided into Suited Tiles, Honor Tiles, and Bonus Tiles: ### Suited Tiles (108 tiles total — 3 suits, numbers 1 through 9, 4 of each tile) - **Characters (Wan / 萬):** Numbered 1 through 9. Marked with the Chinese character for "10,000" (萬). 36 tiles. - **Bamboo (Tiao / 條 / Sou):** Numbered 1 through 9. Depicted as bamboo sticks, except 1 Bamboo which features a Peacock or Sparrow. 36 tiles. - **Dots (Tong / 筒 / Pin):** Numbered 1 through 9. Depicted as round circles or coins. 36 tiles. ### Honor Tiles (28 tiles total, 4 copies each) - **Winds (Feng / 風):** East (東), South (南), West (西), North (北). (16 tiles total). - **Dragons (Jian / 箭):** Red Dragon (Chung / 中), Green Dragon (Fa / 發), White Dragon (Pak / 白板). (12 tiles total). ### Bonus Tiles (8 tiles total, 1 of each) - **Flowers:** Plum (1), Orchid (2), Chrysanthemum (3), Bamboo (4). - **Seasons:** Spring (1), Summer (2), Autumn (3), Winter (4). Note: When drawn, bonus tiles are immediately revealed, set aside, and replaced by drawing a new tile from the back of the wall. --- ## 3. Turn Structure & Flow of Play 1. **Dealing:** At the start of the hand, tiles are shuffled and built into a 4-sided Wall. In 13-tile variants, players start with 13 tiles (Dealer starts with 14). In 16-tile Filipino variants, players start with 16 tiles (Dealer starts with 17). 2. **Turn Sequence:** - **Draw:** The active player draws 1 tile from the wall. - **Evaluate:** The active player checks for win (Tsumo / Self-Draw) or valid Concealed Kong. - **Discard:** If no win is declared, the player discards 1 tile into the table river. 3. **Claims by Opponents:** When a tile is discarded, opponents have a window to claim it: - **Chow (Chi):** Can ONLY be called by the player directly to the discarder's right (next in turn). - **Pong (Peng):** Can be called by ANY player holding 2 matching tiles. - **Kong (Gang):** Can be called by ANY player holding 3 matching tiles. - **Win (Ron / Hu):** Can be called by ANY player whose winning hand is completed by the discarded tile. - **Priority Resolution:** Win takes highest priority. Pong/Kong takes second priority (overriding Chow). Chow takes lowest priority. If passed, play continues with the claiming player's turn. --- ## 4. Melds (Chow, Pong, Kong, and The Eye) - **Chow (Chi / Sequence):** 3 consecutive suited tiles in the same suit (e.g., 3-4-5 of Dots). Honor tiles (Winds and Dragons) cannot form Chows. - **Pong (Peng / Triplet):** 3 identical tiles (e.g., three 8 Bamboo or three Green Dragons). - **Kong (Gang / Quad):** 4 identical tiles. Because a Kong uses 4 tiles instead of 3, the caller draws a replacement tile from the back of the wall (Dead Wall) so their hand does not end up tile-short. - **The Eye (Pair / Mata):** Every standard winning hand requires exactly 1 matching pair of identical tiles. --- ## 5. Regional Rule Variants ### 5.1 Filipino / Visayan Mahjong (16-Tile) - **Hand Size:** 16 tiles in hand; completed hand has 17 tiles (5 Melds + 1 Pair). - **Bunot (Self-Draw):** Winning on a drawn tile (Bunot) pays double from all other players and takes the accumulated table ante pot. - **Siete Pares (7 Pairs):** A special alternative winning hand consisting of 7 distinct pairs plus 1 triplet (17 tiles), bypassing standard 5-meld composition. - **Escalera:** A full sequence from 1 through 9 in a single suit. - **Ante Pot:** Players contribute to an ongoing table pot at the beginning of each hand and when certain flower bonuses occur. ### 5.2 Hong Kong / Cantonese Mahjong (13-Tile) - **Hand Size:** 13 tiles in hand; completed hand has 14 tiles (4 Melds + 1 Pair). - **Faan (番) Scoring:** Hands are scored by evaluating patterns for Faan values. - Ping Hu (All Sequences / Chows): 1 Faan - All Pongs (Pung Pung Wu): 3 Faan - Half Flush (Mixed One Suit + Honors): 3 Faan - Full Flush (Pure One Suit): 7 Faan - Thirteen Orphans (Shi San Yao): Limit Hand (Maximum points) - **Flower Seat Matching:** Players match their seat wind (1: East, 2: South, 3: West, 4: North) to the numbered flower tiles for extra Faan. ### 5.3 Chinese Official / MCR Mahjong (13-Tile) - **Hand Size:** 13 tiles; completed hand has 14 tiles (4 Melds + 1 Pair). - **8-Point Minimum Requirement:** A player cannot declare a win unless their hand scores at least 8 points from the 81 official competition fan patterns. - **Pure Skill / Tournament Standard:** No gambling pots or flower ante luck elements; widely used in international championships. ### 5.4 Japanese Riichi Mahjong (13-Tile) - **Hand Size:** 13 tiles; completed hand has 14 tiles (4 Melds + 1 Pair). - **1-Yaku Minimum:** You cannot declare a win (Ron or Tsumo) without at least 1 valid Yaku pattern. - **Riichi Declaration:** If a player has a closed hand and is Tenpai (one tile from winning), they may declare Riichi, wager a 1,000-point stick, and lock their hand. Winning with Riichi grants +1 Han and access to Ura-Dora. - **Furiten Rule:** If any tile you have previously discarded could complete your current hand, you are in Furiten. You CANNOT win on an opponent's discard (Ron); you may only win via self-draw (Tsumo). - **Dora & Aka-Dora (Red Fives):** Revealed Dora indicators indicate bonus Han tiles. 3 special Red Fives (one 5-Dot, one 5-Bamboo, one 5-Character) provide bonus Han if kept in hand. - **Match Format:** East Match (Tonpuusen) starting with 25,000 points. --- ## 6. Multiplayer Features & Bot AI - **Browser-Based:** Runs on WebSockets with immediate real-time state synchronization. - **4-Digit Room Codes:** Create a table, get a code or share a link. - **AI Bot Substitution:** Any vacant table seat can be filled with an AI bot so games are never stalled waiting for a 4th player. - **Adjustable Bot Speed:** Normal, Fast, or Instant bot actions. - **Guest Play:** Instant entry with no email or registration needed; 24-hour sliding activity window. - **Registered Accounts:** AWS Cognito authentication, persistent usernames, and lifetime stats tracking. --- ## 7. Frequently Asked Questions Q: Why can't I Chow from players across or to my right? A: By traditional international Mahjong rules, a Chow sequence can only be called from the player who discarded immediately before you (your left neighbor). Pong and Kong can be called from anyone. Q: What happens if two players claim the same discard? A: Win takes precedence over Pong/Kong/Chow. If multiple players claim a Win, the player closest to the discarder in turn order wins. Q: Is this real money gambling? A: No. Mahjong by Bossrod is 100% free with virtual points only. There are no real money wagers or prizes. --- ## 8. Safety, Fair Play, and Legal Disclaimers - Platform URL: https://mahjong.bossrod.com/ - Governing Terms: https://mahjong.bossrod.com/terms - Privacy Policy: https://mahjong.bossrod.com/privacy - Compliant with Philippine RA 10173, EU GDPR, and California CCPA.