Variant Sudoku Guides

How the variants work and how to solve them. Each guide covers the rule, the techniques that crack it, and the questions newcomers ask most.

Cages with target sums turn classic sudoku into an arithmetic puzzle. Here's the rule and the techniques that crack it.

Digits climb along each thermometer from bulb to tip. Learn how length alone pins down ranges of candidates.

The circled digit equals the sum along its arrow. A clean variant with surprisingly deep deductions.

Tiny dots between cells encode consecutive and double relationships. Small marks, big chains of logic.

Add two diagonals to a classic grid and the whole solve tightens. The friendliest entry point into variants.

Each purple line is a set of consecutive numbers in any order. Flexible, fast, and great for chaining.

Every digit on the line lives strictly between the two circled bulbs. Simple to state, sneaky to solve.

No digit repeats a chess knight's move away. A spatial constraint that reshapes how the whole grid connects.

Each grey line reads the same forwards and backwards, mirroring digits across its centre.

Neighbouring digits on the green line must differ by at least 5. A deceptively tight constraint built around the 5.

X marks a pair summing to 10, V marks a pair summing to 5. A clean additive variant hiding on the cell borders.

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