Zero elimination
A 0 excludes all four surrounding edges immediately.
SLITHERLINK · GAME-FIRST EXACT LOOP CAMPAIGN
Slitherlink prove one loop, one edge at a time
A focused 90-level path from compact 5×5 boards to long-form 15×15 loops. Hints explain a deduction from your current marks; Daily and Practice stay reproducible, and assisted help never masquerades as a clean solve.
ModeCampaign
Board—
RunClean
Loop—
Campaign solved0/90
All solved0
Clean solved0
Daily records0
Advanced Slitherlink Lab · V0.231 tools, proof lens, archive, print, history & technique training
SLITHERLINK · LOOP THE LOOP · VERIFIED DEDUCTION
Slitherlink prove the loop, edge by edge
Draw one continuous loop without guessing. V0.231 explains the next forced edge, shows live structural evidence, scales through 15×15, and keeps help-assisted runs separate from clean solves.
Moves0
Practice SlitherlinkDeterministic once the URL seed is fixed.
CleanLines —Time 0:00
loop×excludedforced by current logic
Draw one continuous closed loop. Number clues count surrounding loop edges.
Slitherlink
V0.231 LOOP LOGIC LENS
Live logicSee why the next edge is forced
Local deductions come from clue quotas, dot degree and premature-loop prevention. When those go quiet, smaller boards can use an exact constraint proof; every shipped source is pre-certified unique.
Open edges—
Line components—
Forced now—
Proof statusNot checked
Scan ready
The next named deduction appears here with a reason, not as an unexplained answer reveal.
Solved0
Clean solved0
Best this level—
Daily streak0
REPEATABILITY
No assisted deductions used yet.Recent loops and deduction evidence
No completed runs on this device yet.
CLUE QUOTA
Finish or close a clue
If a clue already has its required line count, every other side is excluded. If every remaining open side is needed, all are forced into the loop.
DOT DEGREE
Zero or two lines at every dot
A used dot must have exactly two loop segments. One line plus one open exit forces that exit; two lines exclude every other edge.
LOOP GUARD
Do not close a smaller circuit
If an edge would seal the current component before the whole puzzle is complete, that edge is excluded.
VERIFIED BANK
180 original sources through 15×15
Practice spans 5×5, 6×6, 7×7, 10×10, 12×12 and 15×15 at Easy, Medium and Hard. All source puzzles are unique-solution certified before shipping.
DAILY LADDER
The week naturally climbs in size
Monday starts at 5×5, midweek reaches 7×7–10×10, Saturday uses 12×12 and Sunday offers a 15×15 long-form Daily. Past dates remain replayable.
CLEAN VS ASSISTED
Help never masquerades as clean
Hint, Verify state, mistakes, Check, Undo, Redo and Restart mark the run Assisted. Tool choice, dragging and scrolling do not.
Corner 3
A 3 in a corner forces both boundary edges into the loop.
3 next to 0
The 0 blocks the shared side, forcing all three other sides of the 3.
Adjacent 3 rails
Side-by-side or stacked 3s force the two outer rails parallel to their shared side.
Dot degree
Every touched dot needs exactly two loop edges, which forces exits and blocks branches.
Loop closure guard
Reject an edge that would close a smaller loop before the whole circuit is complete.
Verified consensus
When local logic is silent, the exact model or pre-certified unique source can prove a forced edge.