Rules

The Side Rule:

The Polygon Rule:

The Chain Rule (difficulty level 3 and above):

“Adjacent number cells belonging to different faces must contain the same number”.

“Each number must be single within a face. For example, squares feature numbers 1 to 4, pentagons feature numbers 1 to 5, and so on”.

Shortest Chains:

“All numbers belonging to a short chain must be single”.

Chains appear at difficulty levels 3, 4 and 5. For example, a short triangular chain will have three links featuring all numbers from 1 to 3. A short pentagonal chain will have five links featuring all numbers from 1 to 5 and so on. The higher the difficulty level you choose, the more chains may appear.

Longer Chains:

“All numbers belonging to a chain that is twice as long, as its corresponding short chain, must appear in pairs. If the chain is three times as long then the same numbers must appear in triplets and so on”.

For example, longer triangular chains may feature 2x3, 3x3, 4x3, and so on links, longer square chains may feature 2x4, 3x4, 4x4, and so on links etc. If there are 6 triangular (2x3) links, then each of the numbers 1 to 3 must appear twice within those chain links. If there are 12 square (3x4) links, then each of the numbers 1 to 4 must appear exactly three times.

The number 5 should appear only once while number 2 is missing from this polygon

Number 6 in this cell is incorrect because in a square face with four cells, only numbers 1 to 4 may appear

A notional chain made of three triangular links

Number 5 here is incorrect because in a chain of triangular links only numbers 1 to 3 may appear

Number 2 here is incorrect because in a chain of three triangular links, all numbers 1 to 3 must appear only once.

In the above surface there is a notional chain of eight square links meaning that all numbers 1 to 4 must appear twice inside this group of chain links. The error here is that three instances of number 4 and only one of number 3 have been included.

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