Four Rivers Mahjong

1. Executive Summary & Game Overview

Four Rivers Mahjong—also widely celebrated in puzzle gaming circles as Shisen-Sho, Rivers Mahjong, or Four Rivers Solitaire—is a fast-paced, highly strategic tile-matching game rooted in rich Oriental traditions. While classic Mahjong Solitaire tasks players with dismantling towering, multi-layered 3D pyramids of tiles, Four Rivers Mahjong streamlines the playing field into a sleek, single-layer rectangular grid. However, do not be fooled by its flatter layout; Four Rivers Mahjong introduces an intriguing topological rule set based on pathfinding, line-of-sight visual pathways, and spatial geometry.

In Four Rivers Mahjong, players must match identical pairs of traditional Chinese Mahjong tiles. The catch lies in how the tiles connect: two identical tiles can only be matched and removed if they can be joined by a continuous line that turns no more than two right angles (90-degree turns)—effectively creating a pathway that uses at most three straight line segments (or "four river bends") through open, unoccupied space.

Designed to deliver an intensely satisfying mix of visual scanning, rapid pattern recognition, and long-term tactical planning, Four Rivers Mahjong transforms traditional tile-matching into a dynamic spatial maze. Whether you are looking for a calming mental workout to start your morning or seeking a place on competitive global speed-run leaderboards, Four Rivers Mahjong offers an exceptionally polished, serene, and endlessly replayable puzzle experience. Complete with crisp 4K visual tile sets, customizable backgrounds, relaxing traditional instrumental scores, and intelligent hint assistance, Four Rivers Mahjong stands as an essential masterpiece for all puzzle aficionados.

---

2. Key Features & Highlights

• Classic Shisen-Sho Mechanics: Experience authentic 2-turn (3-segment) pathfinding matching rules across a sleek, flat-grid layout.
• Over 400 Handcrafted Grid Maps: Progress through an expansive campaign featuring diverse grid configurations, ranging from compact $6 \times 12$ grids for beginners to sprawling $10 \times 18$ master arenas.
• Diverse Game Modes:
  • Zen River Mode: Relaxing, untimed puzzle gameplay with unlimited shuffles and hints—ideal for stress-free mindfulness.
  • River Rush (Time Attack): Race against a rapidly ticking countdown clock, earning extra seconds for swift streak combos.
  • Master Challenge: Play on complex layouts where no hints or auto-shuffles are provided; every move must be pre-calculated!
  • Daily River Expedition: Solve a unique, globally shared puzzle board every day to earn collectible badges and trophies.
• Multiple Visual & Audio Themes:
  • Choose between traditional hand-painted Chinese Mahjong tiles, modern minimalist icons, or vibrant neon vector tile sets.
  • Enjoy tranquil ambient soundscapes composed with traditional Guzheng, bamboo flutes, Pipas, and soft river water acoustics.
• Robust Quality-of-Life Tools:
  • Smart Path Finder (Hint): Instantly highlights a valid, matching tile pair and illustrates the connecting path between them.
  • River Flow (Shuffle): Re-arranges un-cleared tiles on the grid when no legal path matches remain available.
  • Time Rewind (Undo): Takes back recent tile removals to let you explore alternate clearing routes.
• Deep Stat Tracking & Leaderboards: Monitor your win/loss ratio, average solve times, fastest clear records, and global ranking positions.

---

3. Detailed How-to-Play Instructions

3.1 The Two-Turn (Three-Segment) Rule

The core mechanic that defines Four Rivers Mahjong is the Line-of-Sight Connection Rule. You can match and remove two identical, unblocked tiles ONLY if you can draw a continuous line between them that meets all of the following conditions:

1. Clear Pathway: The connecting line must pass strictly through empty grid spaces or outside the boundaries of the board. It cannot cross through any other tiles.
2. Maximum of Two Turns: The line can travel straight, make one $90^\circ$ turn, or make two $90^\circ$ turns. It can NEVER turn three or more times.
3. Three Segments Max: A line with two turns consists of three distinct straight line segments (often conceptualized as crossing over "four river banks" or boundary edges).