Overview
In a Yin Yang puzzle every cell holds a circle that is either light (an open ring) or dark (a filled disc). A few circles are printed as clues; you fill in the rest. There is one rule about colour groups and one about 2×2 blocks, and every puzzle has exactly one solution you can reach by pure logic.
The Goal
Fill every empty cell with one circle — light or dark — so the finished grid obeys all three rules below. When you are done, every cell holds a circle and there are no blanks left.
The Rules
A finished grid must satisfy all three:
- Light circles connect. Every light circle is joined to every other light circle in one single group, moving only up, down, left, or right (not diagonally).
- Dark circles connect. Every dark circle is likewise joined into one single group.
- No 2×2 is one colour. No block of four cells in a 2×2 square may be all light or all dark.
That is the whole puzzle: two colours, each in one connected piece, with no solid 2×2 patch of either. The light and dark groups end up interlocking, which is where the name comes from.
The Clues
- The printed circles are givens — your solution must keep them exactly as shown.
- A light clue is drawn as an open ring; a dark clue is a filled disc; an empty cell is left blank. So a light clue always looks different from a cell you still have to fill.
- The clues are placed so the rest of the grid is forced — there is exactly one way to finish the board.
How to Start Solving
Work from the rules, not from guessing. These moves get most boards moving:
- Block solid 2×2s. If three cells of a 2×2 square are already the same colour, the fourth cell must be the other colour — otherwise you would make a forbidden 2×2. This is the most common forced move.
- Don’t wall a colour off. Because each colour must stay in one connected group, watch for a cell whose colour would cut a group in two or trap it in a corner. If colouring a cell one way would strand some of that colour, colour it the other way.
- Mind the edges and corners. Cells on the border have fewer neighbours, so they are often forced early — a corner that can only reach its group one way fixes the cells around it.
- Keep both colours flowing. After each move, glance at both groups: every light circle must still have a path to the other lights, and every dark to the other darks. A move that isolates a single circle is wrong.
- Repeat until every cell is filled and all three rules hold. Because the solution is unique, careful application of these checks always gets you there.
Why It Is a Good Puzzle
Yin Yang is quick to teach — two colours and two ideas (connect each colour, avoid solid 2×2 blocks) — but the connectivity rule makes it genuinely deductive, not just pattern-filling. The interlocking light and dark regions also make a striking printed page, which is why it works well in logic-puzzle books and mixed-logic collections.
Difficulty (and why there is no guessing)
Every Puzzle Maker Pro Yin Yang puzzle has exactly one solution and is solvable by logic alone — no trial and error. The difficulty setting changes how hard that logic is:
- Easy gives you more starting circles, so the forced moves are short and obvious.
- Medium and Hard reveal fewer circles, so you chain the connectivity rule across longer stretches of the board.
- Expert is the sparsest. It still needs no guessing, but it can require a short “if this cell were light, a group would be cut off, so it must be dark” look-ahead.
Outcome
You now know the goal, the three rules, how the clues are drawn, and the first solving moves. Ready to make your own? See How to Create Yin Yang Puzzles in Puzzle Maker Pro.