START WITH SUDOKU — IF YOU WANT PURE LOGIC
Sudoku is the right entry point for most people. A 9×9 grid, some digits already placed, one rule: every row, column, and 3×3 box must contain 1–9 exactly once. No arithmetic. No measuring. No ambiguous rules — just constraint logic.
It's also the most documented number puzzle in the world. If you get stuck, solutions and technique guides are everywhere. And once you can solve Sudoku reliably, almost every other puzzle in GridJoy becomes easier to learn — because they all share some version of the same elimination instinct.
Next step from Sudoku: Killer Sudoku adds arithmetic cage sums on top of the same grid. If you like Sudoku but want a harder entry point that doesn't require starting digits, Killer is the natural upgrade.
START WITH KAKURO — IF YOU WANT ARITHMETIC
Kakuro is the puzzle for people who like number crosswords. A crossword-style grid where every run of white cells has a sum target. Fill each run with distinct digits 1–9 that add up to the target. No row-column-box rule — just arithmetic and the no-repeat constraint per run.
If you've solved number crosswords in a newspaper or magazine, Kakuro will feel immediately familiar. The mental rhythm of "which digits could sum to this?" is distinct from Sudoku's scanning pattern — it's a different kind of thinking, and many players who don't gel with Sudoku find Kakuro clicks faster.
Next step from Kakuro: Calcudoku adds operator variety (×, −, ÷ as well as +) and the Sudoku row/column uniqueness rule, making it the harder combination puzzle.
START WITH NUMBER MAZES — IF YOU WANT SPATIAL PUZZLES
Number Mazes are the most intuitive on first contact. A grid of square cells, a few numbers placed as clues, and a path that visits every cell exactly once from 1 to the total count. Fill in the missing numbers along the path.
The core skill is gap analysis: if two clues are far apart, work out which cells the path must pass through between them. There's no arithmetic and no row/column constraint — just spatial path reasoning. Most people solve their first Number Maze correctly on the first attempt.
Next step from Number Mazes: Hex Mazes use the same rules on a hexagonal grid, giving each cell six neighbours instead of four. More routing options per step; harder to force.
THE PROGRESSION LADDER
Each GridJoy puzzle family has a natural entry and an upgrade path:
Logic family
Sudoku → Killer Sudoku → Calcudoku
Arithmetic family
Kakuro → Number Crossword → Calcudoku
Path family
Number Mazes → Hex Mazes → Starlink
Constraint family
Hitori → Takuzu → Shikaku
Other starting points
Inequality, Skyscraper, Sumplete, Countdown, Number Blocks — each standalone; read the info page first
WHAT NOT TO START WITH (AND WHY)
These puzzles aren't harder — they're just counterintuitive on first contact. Learn one of the entry-level puzzles above first, then come back:
Hitori: You shade cells to satisfy two constraints simultaneously (no repeats in rows/columns AND all unshaded cells stay connected). The shading mechanic feels awkward before the pattern clicks. Give it one or two sessions after Sudoku.
Shikaku: Divide a grid into rectangles such that each rectangle contains exactly one given number, and that number equals the rectangle's area. Area-partition reasoning is non-obvious until you've seen the "corner-forcing" trick.
Skyscraper: Place 1–N in each row and column so that the view clues at the grid edges are satisfied (each clue counts how many buildings of increasing height are visible). Needs the Sudoku row/ column uniqueness instinct plus a second layer of height reasoning.
None of these are bad puzzles — they're among GridJoy's most elegant types once you've built up the right instincts. Just not ideal as first contacts.
THE QUICK DECISION
No arithmetic, familiar grid → Sudoku
Like number crosswords → Kakuro
Want to trace a path → Number Mazes
Want a quick daily habit → Sudoku Daily (free, one puzzle per day in the browser)
Already solved Sudoku before → Killer Sudoku or Calcudoku