Knot Theory

Controls

Drag a pin with the mouse or your finger to move it, and tap the Hint, Undo, Reset and Levels buttons on screen. On a keyboard, Tab picks the next pin (Shift+Tab or Q goes back), the arrow keys or WASD move it and Enter or Space sets it down; U or Z undoes, H is a hint, R resets and L opens the level list. P or Esc pauses.

How to play Knot Theory

Each level is a board of round pins joined by colored elastic ropes, and the ropes start out in a tangle. Ropes that cross glow red, and a red dot marks every crossing. Drag the pins around until no two ropes cross anywhere on the board.

A pin also can’t rest on top of a rope that isn’t its own, so leave a little space. The counter above the board shows how many crossings are left. Clear the last one and the ropes turn gold: the knot is untangled.

Levels, nailed pins and stars

There are 32 levels. The first has 5 pins and the last has 25, and later boards pack in more ropes per pin. Some tangles start with the loose pins arranged in a ring, others with the pins scattered across the board. From level 6 on, steel pins marked with an X are nailed down and can’t be moved: one on the early boards, then two, then three on the hardest ones.

Every level has a par number of moves, and each drag that moves a pin counts as one move. Untangle the board within par for three stars, within a little under twice par for two, and with any number of moves for one. Levels unlock one after another, and the level list lets you replay any level you have opened.

Tips and tricks

• Start with the pins on red ropes. Pulling one of them to the edge of the board often clears several crossings at once.
• Nailed steel pins are already in the right place, so build the rest of the layout around them.
• On a keyboard, Tab jumps to pins that sit on crossing ropes before the others.
• Undo is free, and so is Reset if you want to start the board over.
• Stuck? Tap Hint and watch a short ad: one pin glides to its place in a real solution. You get up to three hints per level, and a hint does not add to your move count.