How do you solve a Yin-Yang puzzle?

Start by looking for 2×2 areas that already contain three cells of the same colour — the fourth cell must be the opposite colour. Then check for cells that, if coloured one way, would split the other colour into disconnected groups. Use connectivity logic to trace paths of each colour from the givens outward.

What grid sizes are available?

Five sizes: 6×6, 8×8, 10×10, 12×12, and 14×14. Smaller grids are quick and beginner-friendly, while larger grids require more advanced connectivity reasoning.

What difficulty levels are there?

Three levels: Easy (many given cells, solvable with basic 2×2 deductions), Medium (fewer givens, requires connectivity logic), and Hard (minimal givens, requires deep connectivity analysis and trial elimination). All puzzles have exactly one solution.

Is Yin-Yang related to other logic puzzles?

Yes. Like Nurikabe, Yin-Yang revolves around connectivity constraints. Like Takuzu (Binary), it is a two-colour placement puzzle. However, Yin-Yang uniquely combines connectivity requirements for both colours with a 2×2 constraint, making it a distinct and satisfying challenge.

Play Yin-Yang Online

Q: What is the Yin-Yang puzzle?

Yin-Yang is a binary logic puzzle played on a square grid. The goal is to fill every cell with either a black or a white circle while obeying two rules: both the black cells and the white cells must each form a single orthogonally connected group, and no 2×2 block of cells may be entirely the same colour.

Fill every cell with a black or white circle. Both colours must form a single connected group and no 2×2 area can be all one colour. Five grid sizes and three difficulty levels.

Filled

0 / 0

Errors

Time

0:00

Click a cell to place a circle

Yin-Yang puzzle — fill cells with black and white so each color forms a connected group

What Is the Yin-Yang Puzzle?

Yin-Yang is a binary logic puzzle played on a square grid. Some cells start pre-filled with either a black or white circle. Your task is to fill every remaining cell with one of these two colours so that two simple rules are satisfied simultaneously.

The puzzle draws its name from the ancient yin-yang symbol, which represents the balance and interconnection of opposing forces. In the puzzle, this duality is expressed through two complementary colours that must each form a single unbroken region — perfectly mirroring the intertwined halves of the symbol. Yin-Yang puzzles have appeared in logic puzzle magazines, competition puzzle sets, and online puzzle platforms.

Rules of Yin-Yang

Connectivity: All black circles must form a single orthogonally connected group (connected horizontally or vertically, not diagonally). Likewise, all white circles must also form a single connected group.
No 2×2 squares: No 2×2 block of cells may be entirely the same colour. In other words, every 2×2 region must contain at least one black circle and at least one white circle.

These two rules together create a surprisingly rich puzzle. The connectivity constraint means each colour must wind its way through the grid as a connected path or blob, while the 2×2 rule prevents either colour from forming large solid blocks.

How to Solve Yin-Yang — Strategy Tips

1. Check 2×2 Blocks

The most basic deduction: look for any 2×2 area that already contains three cells of the same colour. The fourth cell must be the opposite colour. This is similar to the “no three in a row” rule in Binary (Takuzu) and provides many immediate placements, especially on easy puzzles.

2. Use Connectivity Logic

If placing a colour in a particular cell would cut the opposite colour’s group into two disconnected pieces, that placement is impossible. Trace paths from given cells of each colour and consider whether a colour choice would create an isolated pocket. This is the most powerful technique in Yin-Yang solving.

3. Follow Edges and Corners

Cells along the edges and in corners are especially constrained. A colour that appears in a corner must be able to connect to all other cells of the same colour. Two given cells of the same colour on the same edge must have a connected path between them — and the cells along that path are often forced.

4. Avoid Creating Isolated Regions

As you fill cells, watch for situations where an unfilled area has only one connection point to the rest of a colour’s group. If that connection point is coloured the wrong way, it would create a disconnected island. This technique becomes critical on medium and hard puzzles.

5. Trial and Elimination

When deduction stalls, pick an ambiguous cell and hypothetically colour it. If that colour leads to a forced contradiction — either a 2×2 mono-colour block or a disconnected group — the other colour must be correct. Hard puzzles frequently require this technique.

Grid Sizes

6×6: A quick warm-up. Most cells can be deduced just from the 2×2 rule. Great for learning the mechanics.
8×8: Introduces meaningful connectivity logic. Puzzles take 3–5 minutes for an intermediate solver.
10×10: A solid mid-level challenge. Both the 2×2 rule and connectivity analysis are needed throughout.
12×12: Challenging. Longer connectivity chains and more ambiguous regions demand careful reasoning.
14×14: Expert-level. Dense grids that require all techniques plus patience and systematic elimination.

Difficulty Levels

Easy: Many given cells. The 2×2 rule alone solves most cells. Ideal for beginners learning Yin-Yang for the first time.
Medium: Fewer givens. Connectivity reasoning is required alongside 2×2 deductions.
Hard: Minimal givens. Deep connectivity analysis and trial elimination are necessary. All puzzles have exactly one solution.

Yin-Yang vs Similar Puzzles

vs Nurikabe: Both puzzles involve connectivity constraints. In Nurikabe, numbered islands define region sizes and only the “sea” must connect. In Yin-Yang, both colours must independently form connected groups, making it a dual-connectivity challenge.
vs Binary (Takuzu): Both are two-colour grid puzzles, but Takuzu uses “no three in a row” and equal-count rules whereas Yin-Yang uses connectivity and a 2×2 constraint. The feel is quite different despite the binary palette.
vs Hitori: Hitori uses shading and connectivity (unshaded cells must connect), but adds row/column uniqueness and adjacency rules for shaded cells. Yin-Yang’s dual-connectivity is a unique twist.

Frequently Asked Questions

A logic puzzle on a square grid. Fill every cell with a black or white circle so that all black cells form one connected group, all white cells form one connected group, and no 2×2 area is entirely one colour.

Look for 2×2 areas with three cells of the same colour — the fourth must be opposite. Then use connectivity logic: if colouring a cell would disconnect the opposite colour, it cannot be that colour. On harder puzzles, trial-and-error elimination may be needed.

Five sizes: 6×6, 8×8, 10×10, 12×12, and 14×14. Smaller grids are quicker and more beginner-friendly while larger grids demand deeper reasoning.

Yes. Every puzzle generated here has exactly one valid solution, verified by a backtracking solver before the puzzle is presented.

Yes. It shares connectivity constraints with Nurikabe and the two-colour placement with Binary (Takuzu). However, Yin-Yang’s requirement that both colours form connected groups alongside the 2×2 rule makes it distinct.

More Logic Puzzles

Enjoy Yin-Yang? Try these other free puzzles:

Nurikabe

Shade cells to form a connected sea around numbered islands.

Binary (Takuzu)

Fill the grid with 0s and 1s — no three in a row, equal counts, unique lines.