⚡ Pipe Loop

A calm daily wire puzzle

Pipe Loop is a relaxed logic puzzle about untangling a broken circuit. The board starts scrambled: every scrap of wire is turned the wrong way, so nothing connects. Rotate the tiles one quarter-turn at a time until each end meets a partner and the whole thing closes into a single continuous loop. There is no timer pressure and no way to lose — the clock is just a stat for people who like to race themselves.

Daily stays fixed; practice grows with you

The daily seed is simply today's date, and the board size rotates through 5×5, 7×7 and 9×9 with the day of the month, so a reload never hands you an easier puzzle. Easy, Medium and Hard behave differently. Each one you solve in a row lays down slightly more wiring, and every second solve adds a row and a column — up to 8×8, 10×10 and 11×11 respectively. Changing difficulty resets that streak and starts the climb again.

That is the unusual part: Pipe Loop is the only game in the arcade with a reason to come back tomorrow rather than in five minutes, and every board has a solution waiting. The other grid games do the opposite — Inkworm and Merge Press take arrow keys or a swipe and end when you have painted yourself into a corner, while Ink Breaker and Tipping Press want more attention: one is a block-breaker where the paddle steers the ball, the other a balance puzzle where the beam tips if you load it wrong. All four end when you make a mistake rather than when the board is complete.

How today's board gets made

The daily board is not fetched from anywhere. It is rebuilt from scratch in your browser every time you open the page, from a single number: today's date written as YYYYMMDD. That number is fed to a small deterministic pseudo-random generator (mulberry32), and every choice the builder makes afterwards comes out of that one stream. Same date, same stream, same board — which is why two people on opposite sides of the world can compare move counts without either of them having downloaded anything. It also means a reload cannot hand you a kinder puzzle, because there is nothing to re-roll.

The loop itself is grown rather than drawn. The builder drops a 2×2 square of wire somewhere on the grid — the smallest possible closed loop — and then repeatedly picks one edge of that loop and pushes it outward by two cells into empty space, reconnecting as it goes. Every push keeps the shape a single closed loop with no crossings and no branches, and every push adds exactly two tiles, so the finished wire count is always even. It keeps pushing until it has covered its target share of the grid, which is where the difference between Easy and Hard actually lives: Easy fills about 92% of a small grid, Hard only about 70% of a bigger one. The empty cells left over are not decoration — they are walls, and a wire pointing into one is an error exactly like a wire pointing off the board.

Once the loop exists, every tile is turned off its correct orientation by a random amount — one to three quarter-turns for a corner, one for a straight, since a straight only has two distinct states. That guarantees no tile starts correct, which is why Par is never zero: it is the total number of quarter-turns needed to walk every tile back to the orientation the builder gave it. Corners can cost two, straights always cost one. On the rare occasion the scramble happens to come out solved, it is thrown away and rolled again.

Practice differs in two ways worth knowing. Its seed is a fresh random 32-bit number rather than the date, so New always means new. And it ramps: each puzzle you solve without changing difficulty widens the next board and packs a little more wire into it, up to a ceiling. Daily never ramps — it is the same size for everyone all day. Pressing New while you are on the Daily tab does not reroll the daily; it moves you to Medium, because there is nothing to reroll.

A solving order that works

Every tile holds exactly two connectors, and the finished board is one closed loop. Those two facts together mean most of the board can be reasoned out rather than guessed at: the job is to keep finding the tile whose options have already been narrowed to one. Work in this order and the board largely solves itself.

1. Start with the four board corners. A wire sitting in a corner of the grid has two of its four sides against the outside world, so both of its connectors are forced inward. There is exactly one legal orientation and no thinking required. Set them, and you have four anchors to grow from.
2. Walk the outer edges next. An edge tile can never point outward. That kills one of its four sides outright, which fully determines every straight piece on an edge — it has to run along the edge — and cuts every corner piece down to two candidates. Do the whole perimeter before touching anything in the middle.
3. Treat every gap as another wall. The empty cells scattered through the board behave exactly like the outside: a wire may not point at one. On Hard, where nearly a third of the grid is empty, this is where most of the free information is. Any tile with two or three sides facing gaps or edges is forced or nearly forced, and Hard boards are full of them.
4. Then propagate inward from what you have fixed. A settled tile tells its neighbour something: if it points at that neighbour, the neighbour must point back; if it does not, the neighbour must not. Follow that chain around the loop rather than jumping to whatever looks interesting. The interior of the board carries almost no information on its own, which is why starting there feels like guesswork — it is.
5. Use the spark as a check, not a hint. The game counts how many wire ends are reciprocated by their neighbour, and plays a small spark whenever a rotation makes that number go up. It is honest feedback that a turn was productive, but it will happily reward a locally correct choice that belongs to a different loop shape. Trust the deduction; treat the spark as a receipt.

The clock, incidentally, does not start when the page loads. It starts on your first rotation, so reading the board first costs you nothing at all.

What is kept between visits

Very little, and all of it in this browser's own local storage:

• cl_best_YYYYMMDD — your best result for that specific day, stored as a move count and a time. One key per date, daily mode only; practice results are never saved.
• cl_sound — 1 or 0, whether you muted the sound.
• kp_rank_name — the name you last typed into the leaderboard box, so you do not retype it.
• cl_rank_last — the timestamp of your last leaderboard post, used only to enforce a 30-second gap between posts.

The board itself is never stored, because it is cheaper to rebuild from the date than to keep. Posting to the leaderboard is a separate, deliberate action: when you type a name and press Post after a win, one record leaves your browser — the game name, the name you typed, a score derived from par, moves and time, and a server timestamp. Nothing else, and nothing at all until you press the button.