MyRin Infinity Loop: Rules and Solving Techniques

Infinity Loop hands you a lattice of wire pieces, every one of them turned the wrong way, with lightning-bolt sources at some ends and lamps at the others. Your job is to turn the pieces until power runs from every bolt to every lamp and no wire is left dangling. Random tapping works on small boards and fails on large ones. This guide explains the deduction method that solves any Infinity Loop board, from the edges inward.

Infinity Loop (回路)

Infinity Loop is a MyRin rotation puzzle in which wire tiles on a grid are turned a quarter turn at a time until every wire end meets another and power flows from the lightning-bolt sources to every lamp, with pieces lighting up only when current actually reaches them.

How to play Infinity Loop: the direct answer

Tap a piece to rotate it a quarter turn. A piece lights only when power reaches it from a bolt through wire that meets on both sides of every joint; nothing is coloured for merely being in the right position. Lamps stay dark until the circuit arrives. The level is solved when every lamp is lit, every wire end meets another, and power reaches the whole lattice.

The Japanese name, 回路 (kairo), means "circuit", which is exactly what you are building.

The one rule behind every deduction

Every solving technique comes from a single constraint: two neighbouring pieces either both point at their shared side, or neither does. A wire that points at a neighbour with no wire facing back is a dangling end, and the board cannot be solved with it.

That rule makes the puzzle local. You never need to picture the whole circuit. You only need to ask, for one piece at a time, which rotations are consistent with the neighbours you already know.

Know your pieces: how many positions each really has

Piece	Arms	Distinct orientations	On a border (not a corner)
Dead end	1	4	3
Straight	2, opposite	2	1 (parallel to the edge)
Corner	2, adjacent	4	2
T piece	3	4	1 (open side faces inward)
Cross	4	1	cannot sit on a border

Two facts in that table save most of the work. A straight pipe looks identical after half a turn, so it only has two real positions, not four. And on a border, a straight or a T piece has exactly one legal position, because no arm may point off the board. In a grid corner, a corner piece also has exactly one: both arms pointing inward.

The edge-first method, step by step

1. Lock the grid corners. A corner piece in a grid corner has one position. Set it.
2. Lock the border straights and T pieces. Each has one legal position on an edge. Set them all before touching anything else.
3. Propagate inward. Every piece you lock tells its inner neighbour whether it needs an arm on the shared side. Use that to eliminate rotations one piece at a time.
4. Place dead ends early. A dead end has exactly one neighbour it can face. As soon as three of its four sides are ruled out, it is solved, and it is often the tile that unlocks a stuck region.
5. Follow the light. The glowing wire is the part you have already solved. Extend it one piece at a time from the bolt rather than turning pieces far away from it.

If you get stuck, look for the most constrained piece left: the one with the fewest legal rotations given its neighbours. There is almost always one with a single option.

Why deduction beats tapping

A board of 36 pieces with up to four positions each has an astronomical number of combinations, far too many to find by trying. Puzzles in this family, where tiles must be turned or placed so that touching edges agree, are known as edge-matching puzzles, and in their general form they are NP-complete, as Demaine and Demaine showed in 2007. In practical terms: there is no known shortcut that solves every possible board quickly.

Well-designed levels avoid that trap by being solvable through chains of local deductions, exactly the edge-first method above. The skill the game trains is constraint propagation: fixing what is certain, and letting each certainty narrow the options around it. It is the same skill behind Hashi and Nurikabe, the Nikoli-style logic puzzles MyRin also includes.

Common mistakes

• Starting in the middle. Central pieces have the most freedom and the least information. Start where the board edge removes options.
• Turning straights four times. Two taps bring a straight back to where it started. If neither position works, the problem is a neighbour.
• Ignoring dark wire. Wire that looks connected but is not lit is not connected to a bolt. Trace back from the glow to find the break.

If you enjoy Infinity Loop, try One Line and Nexus, the other path-building puzzles in MyRin. MyRin is free on iOS and Android with 30 games and 18,000 levels; the full list is on the MyRin games page.

FAQ

How do you play Infinity Loop in MyRin?

Tap a wire piece to turn it a quarter turn. The board has lightning-bolt sources at some wire ends and lamps at others. A piece lights only when power actually reaches it from a bolt through wire that meets on both sides. The level is solved when every lamp is lit and no wire end is left dangling.

Where should I start an Infinity Loop puzzle?

Start at the corners and edges. A piece on the border cannot point outward, which often leaves it only one legal rotation. Each piece you settle tells its neighbours whether they need a connection on the shared side, so the solution spreads inward from the border.

Why do some pieces seem to have fewer positions?

Because symmetric pieces repeat themselves. A straight pipe looks the same after half a turn, so it has only two distinct orientations, and a four-way cross has only one. Dead ends, corners and T pieces have four. Knowing this halves the work on every straight piece.

Is Infinity Loop just trial and error?

No. Every well-designed level can be solved by deduction: each piece must connect to its neighbours on exactly the sides where they connect back. Tapping at random works on tiny boards but becomes hopeless on large ones, while the edge-first deduction method scales to any size.