Slitherlink
Play Slitherlink free online: draw a single closed loop around numbered cells where each number tells how many edges are used. A pure logic puzzle with Retro Coins.
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How it works
Play, earn points and Retro Coins: the shared currency across every RetroPlayNow game. Unlock badges and climb the leaderboard! Your progress is saved automatically on this device.
Slitherlink, also known as Fences or Loop the Loop, is one of the purest logic puzzles ever devised. A grid of dots surrounds cells that may contain a number from 0 to 3. Your task is to connect adjacent dots with horizontal and vertical lines to form a single closed loop, such that each numbered cell has exactly that many of its four edges used by the loop.
There are no colors to match, no arithmetic to perform, no words to guess. The entire puzzle is logic distilled to its essence. Every numbered cell is a clue, and every clue constrains its neighbors. A 3 in a corner almost forces the solution. Two 3s side by side create a recognizable pattern. A 0 means none of that cell's edges can be used.
The joy of Slitherlink is the gradual emergence of certainty. You start by marking edges that must be part of the loop (with a line) and edges that cannot (with an X). Slowly, the loop takes shape — and when it finally closes, the satisfaction is immense.
Our RetroPlayNow version features procedurally generated puzzles at multiple sizes, edge-marking tools (line and X), error detection to catch contradictions, and a timer that feeds into the leaderboard. Every loop completed earns Retro Coins.
How to play Slitherlink
- Draw the loop. Connect adjacent dots with lines to form a single closed loop. The loop cannot branch or cross itself.
- Satisfy the numbers. Each numbered cell must have exactly that many of its four edges used by the loop. A 0 means none of its edges are used.
- Mark impossible edges. Use X marks on edges that cannot be part of the loop. This helps you visualize constraints and avoid contradictions.
- Look for patterns. A 3 in a corner forces two edges. Two adjacent 3s create a known pattern. A 0 eliminates all four edges of that cell.
- Earn Retro Coins. Complete puzzles to score points based on size and solving time. Faster solutions earn more Retro Coins.
