How to Play Slitherlink
Overview
Draw a single continuous loop on the grid by connecting dots along cell edges. The loop must not cross or branch, and must satisfy all the number clues.
Video Tutorial
Rules
- 1Draw lines to form exactly one closed loop - no crossing, no branching.
- 2Each number shows how many of its 4 edges are part of the loop.
- 3Empty cells have no constraint on their edges.
- 4Each intersection must have exactly 0 or 2 lines (no dead ends).
Number Meanings
0
No edges
1
1 edge
2
2 edges
3
3 edges
Controls
Click EdgeToggle line on/off
Right-clickMark edge as "no line" (×)
Ctrl+ZUndo last move
Solving Strategies
Start with 0s and 3s
0s have no edges. 3s in corners force specific edge patterns.
Adjacent 3s
Two adjacent 3s create a specific forced pattern around them.
Prevent Small Loops
If a line would close a loop too early, that move is invalid.
Use X Marks
Mark edges that can't be part of the loop to help visualize.