How to Play Slitherlink - Rules Explained Simply

Slitherlink has exactly three rules. Draw lines between dots to make one single loop; each number tells you how many sides of the loop surround that number; the loop cannot cross itself or branch. That is the whole game — everything else is deduction. (Source: official Steam description of Slitherlink: Line Logic.)

Rule 1: One Single Loop

The lines you draw must eventually connect into one continuous loop. Not two loops, not an open line — a single closed circuit. When you are mid-puzzle, unclosed ends are fine; the finished grid must close them all into the one loop.

Rule 2: The Numbers Are Counts

Each numbered cell says how many of its four sides are used by the loop:

• A 0 means no line touches that cell — all four edges around it are crossed out.
• A 3 means three of its four sides are lined.
• Cells without numbers have no constraint — the loop can use any of their edges.

Rule 3: No Crossing, No Branching

The loop never crosses itself and never branches. Any dot has either 0 or 2 lines meeting at it — never 1, never 3 or 4. This single observation powers most of the solving techniques in our beginner strategies.

How Do You Win?

Every puzzle in this game has exactly one solution, always reachable by logic — the official page guarantees no guessing is ever required. You finish when the one loop is closed and every number is satisfied.

Related Guides

• Beginner Strategies
• About the Game
• Difficulty Guide

FAQ

What happens if I make a wrong line? You redraw it — the game is pencil-and-paper logic at heart. Undo habits and keyboard-only play are supported (official feature categories). (input specifics beyond the categories are not documented)

Where do the numbers come from? From the puzzle itself — they are the clues given to you, and they fully determine the unique solution.