Arrow Puzzle Difficulty Levels: Board Sizes and Measured Stats
Arrow Puzzle Hub has four board sizes. Instead of guessing how hard each one is, we generated 300 boards per level with the game's own generator and measured them.
The numbers
| Level | Grid | Avg. arrows | Avg. squares per arrow | Avg. free arrows at start | Avg. clearing rounds (min–max) |
|---|---|---|---|---|---|
| Easy | 6 × 6 | 20.0 | 1.4 | 8.7 | 4.7 (3–8) |
| Medium | 9 × 9 | 24.0 | 2.8 | 11.2 | 5.0 (3–8) |
| Hard | 13 × 13 | 36.9 | 3.5 | 16.4 | 6.1 (4–10) |
| Expert | 18 × 18 | 51.1 | 4.7 | 22.7 | 7.2 (4–11) |
Method: seeds 100000–100299 at each level (300 boards each, 1,200 in total), generated by the same code that runs on the home page. All 1,200 boards were solved by a simple solver (remove every free arrow, repeat); none got stuck. Averages are rounded. Script: tools/board_stats.js in the site's source bundle.
What the columns mean
- Avg. arrows – how many arrows you must remove.
- Avg. squares per arrow – arrow length including bends. Longer arrows block more lanes and are harder to read.
- Free arrows at start – how many arrows can leave on your very first move. More free arrows means more safe starting points.
- Clearing rounds – if you remove every free arrow at once, then repeat, this is how many rounds it takes. It is a rough measure of how deep the dependency chains run.
What the data says
- Easy and Medium have a similar arrow count (about 20 vs 24), but Medium's arrows are twice as long on average (2.8 vs 1.4 squares), so each one blocks more.
- Hard and Expert add both more arrows and longer ones. Expert averages about 51 arrows of ~4.7 squares each.
- The chains get deeper, but slowly: from about 4.7 rounds on Easy to about 7.2 on Expert. Bigger boards are mostly more to scan, not wildly more complicated logic.
- Roughly three quarters or more of every grid is covered by arrows, so boards look full at every size.
Caveat: these are structural measurements, not a study of human players. How hard a board feels depends on you, your screen and how well you read bent arrows. We have not measured solve times across many people.
Which level should I play?
- New to the game: Easy in Relaxed mode – read the rules, then poke at the board.
- Want a daily habit: Medium – it is the size of the daily puzzle.
- Want to practise scanning: Hard, with the habits from the strategy guide.
- Want a long sit-down puzzle: Expert. Phones work, but a larger screen makes the bends easier to read.