1# Nurikabe23Build islands from numbered clues while keeping the sea connected.45## How to Play67Each number is an island clue. Mark cells as island or sea until all rules are true:891. Every island contains exactly one clue.102. Island size equals clue value.113. All sea cells are one connected region.124. No 2x2 sea block is allowed.1314Clue cells are fixed and always island cells.15Once every sea cell is marked, any remaining undecided non-sea cells count as16island for completion.1718## Controls1920| Key | Action |21|-----|--------|22| Arrow keys / WASD / hjkl | Move cursor |23| `x` | Set sea |24| `z` | Set island |25| `Backspace` | Clear to unknown |26| `Ctrl+R` | Reset puzzle |27| `Ctrl+H` | Toggle full help |28| `Escape` | Return to main menu |2930## Mouse3132| Action | Effect |33|--------|--------|34| Left click | Move cursor, or set sea on the current cell |35| Left drag | Paint sea from the current cell |36| Right click / drag | Set island cells |3738## Modes3940| Mode | Grid | Description |41|------|------|-------------|42| Mini | 5x5 | Gentle introduction |43| Easy | 7x7 | Balanced logic |44| Medium | 9x9 | Moderate deduction |45| Hard | 11x11 | Lower clue density |46| Expert | 12x12 | Sparse clues and longer chains |4748## Elo Difficulty4950Named modes are compatibility presets. Use `--difficulty <0..3000>` to target a51specific Elo difficulty for generated puzzles.5253## Quick Start5455```bash56puzzletea new nurikabe mini57puzzletea new nurikabe medium58puzzletea new nurikabe expert59puzzletea new islands easy # alias60```