Learn the techniques

From the rules to the hardest patterns, on real puzzles. Each lesson gives XP; each chapter gives a badge.

  1. RulesFree
    0 of 3
  2. Single cells
    • Single-cell block
    Locked
  3. Last cell
    • Last cell in block
    • Last cell in row or column
    Locked
  4. Claims and shapes
    • Block claims a row or column
    • Block shape
    • Diagonal pair
    Locked
  5. Shapes after marks
    • Remaining block shape
    • Pair squeeze
    • Full row and column
    Locked
  6. Line reasoning
    • Row or column shape
    • Only block in row or column
    • Wide pair squeeze
    Locked
  7. Combined claims
    • Blocks claim rows or columns
    • Rows or columns hold blocks
    • X-Wing
    Locked
  8. Larger patterns
    • Swordfish and Jellyfish
    • Many blocks claim rows or columns
    • Pair chain
    • Paired blocks
    Locked
  9. Test placements
    • Would empty a block
    • Long pair chain
    Locked
  10. Trial
    • Squeezes blocks
    • Forcing chains
    Locked