✏️ One Stroke
Draw a single unbroken line that fills every lit cell exactly once.
SIZE
LEVEL 0FILLED 0/0BEST —
How to play One Stroke
- Press Start to generate a shape made of lit cells.
- Begin on the ringed cell and drag through neighbouring lit cells to extend your line.
- You cannot cross a cell twice. Drag back onto the previous cell to undo a step.
- Cover every lit cell in one continuous stroke to solve the puzzle.
Controls
| Input | Action |
|---|---|
| Drag / swipe | Trace the line |
| Drag back | Undo the last cell |
| Clear | Start the line over |
| Ctrl+F | Enter or leave full screen |
| Esc | Leave full screen |
Tips & strategy
- Corners and dead-ends have only one way in or out — plan to visit them without trapping yourself.
- If a cell would leave an unreachable island behind, it is the wrong next step.
- Start by working out the exit route from tight pockets, then fill the open middle last.
- Every puzzle is built from a real path, so a single-stroke solution always exists from the ring.
Frequently asked questions
Is every puzzle solvable?
Yes. Each board is carved out by a random self-avoiding walk, so a complete one-stroke path always exists starting from the ringed cell.
Why must I start on the ring?
The ring marks the one endpoint the generated path is guaranteed to run from, so you always have a fair route to every cell.
How is my score tracked?
Your record is the fastest solve time, saved per grid size in your browser.