Suguru vs Killer Sudoku: What's the Difference?

Both Suguru and Killer Sudoku are grids broken into cages that you fill with numbers, so it's no surprise that people who enjoy one go looking for the other. But underneath the shared cage look, they're built on completely different foundations. Killer Sudoku is a Sudoku at heart, with all the row, column and box discipline that implies, plus a layer of addition. Suguru tosses out the Sudoku rulebook entirely and runs on a single elegant idea about which numbers may sit next to each other. Here's a clear comparison of Suguru vs Killer Sudoku — the rules, the feel, and which to reach for. Fancy the simpler, maths-free option? Play a Suguru puzzle and see.

The quick distinction

Here's the cleanest way to keep them straight:

• Killer Sudoku is a Sudoku with sum-cages added on top. It keeps every Sudoku rule and layers arithmetic over it.
• Suguru is its own puzzle — no Sudoku rules at all, no sums, just cages filled 1-to-N and a rule that identical numbers can't touch.

One is a Sudoku variant; the other only looks like one.

How Killer Sudoku works

A Killer Sudoku starts as a standard 9×9 Sudoku: every row, every column, and every 3×3 box must contain the digits 1 to 9 exactly once. Then it adds a twist. The grid is divided into dotted-outline cages, each showing a small total, and the digits in a cage must add up to that total without repeating within the cage.

So you're solving a full Sudoku and doing arithmetic at the same time, using the cage sums as extra clues. Unusually, a Killer Sudoku often starts with no given digits — the cage totals are your only starting information.

How Suguru works

Suguru is far more pared-back. Its grid is divided into cages of varying sizes, and there are just two rules:

1. Each cage of N cells holds the digits 1 to N, once each. A four-cell cage holds 1, 2, 3 and 4.
2. No two identical digits may touch — orthogonally or diagonally.

There are no sums — cages aren't totals to reach, just runs of digits to place. And there's no row, column or box rule — a digit can appear many times in a row, as long as no two copies are neighbours. Everything hinges on that diagonal-inclusive no-touching rule.

Side by side

	Killer Sudoku	Suguru
Underlying grid	Always a 9×9 Sudoku	Any size, 6×6 up to 14×14
Sudoku rules?	Full (row, column, box)	None
What the cages mean	Digits that add to a total	The digits 1 to N (cage size)
Maths involved	Yes — addition	None
Adjacency rule	No	Yes — no equal digits touching, incl. diagonally
Can a digit repeat in a row?	No	Yes, if the copies don't touch

The single biggest difference is that Killer Sudoku keeps the entire Sudoku ruleset — so a digit can never repeat in a row, column or box — while Suguru has none of that, allowing repeats as long as they don't touch. That one distinction completely changes how you reason through each puzzle.

Which feels harder?

Killer Sudoku tends to feel heavier, because you're juggling three things at once: the full Sudoku logic, the cage sums, and the arithmetic to work them out. It's a meatier, more demanding solve, and a genuine challenge for experienced Sudoku players.

Suguru is lighter and quicker to pick up. With no sums and no row/column rule, the only constraint to track is adjacency, which makes it more approachable and, for many, more relaxing. It still scales to tough grids, but it never asks you to add a single number. If Killer Sudoku feels like a workout, Suguru is more of a pleasant stroll that occasionally makes you think hard.

Which should you play?

If you're a devoted Sudoku solver who wants more — extra rules, a touch of arithmetic, a tougher grind — Killer Sudoku builds directly on what you know. If you'd like the satisfying logic of a cage puzzle without the Sudoku baggage or the sums, Suguru is the cleaner, friendlier choice, and a great introduction to cage-based number puzzles. Both have a single solution reachable by logic, so neither is a gamble.

The easiest way to decide is to try the maths-free one and see how it suits you. Play a Suguru puzzle now, or read the rules first. And if you also enjoy arithmetic cages, our Suguru vs KenKen comparison covers another close cousin.

Frequently asked questions

What is the difference between Suguru and Killer Sudoku?

Killer Sudoku is a Sudoku variant: it keeps the full 9×9 rules (1 to 9 once per row, column and box) and adds cages whose digits must sum to a total without repeating. Suguru has no Sudoku rules and no sums — each cage simply holds the digits 1 to N, and no two identical digits may touch, including diagonally. The biggest difference is that Killer Sudoku enforces the row/column/box rule while Suguru does not.

Is Suguru easier than Killer Sudoku?

Most people find Suguru easier to pick up, because it has no arithmetic and no row/column/box rule — just cages filled 1-to-N and the no-touching constraint. Killer Sudoku layers cage sums on top of full Sudoku logic, making it a heavier solve. Suguru still scales to hard grids, but it's the gentler of the two.

Are Suguru and Killer Sudoku the same puzzle?

No. They both use cages, which makes them look related, but they're built differently. Killer Sudoku is a 9×9 Sudoku with sum-cages, while Suguru is a stand-alone logic puzzle with no Sudoku rules and no sums, relying on a diagonal-inclusive no-touching rule.

Should I play Suguru or Killer Sudoku first?

If you already love Sudoku and want a tougher, arithmetic-flavoured challenge, start with Killer Sudoku. If you want a friendlier, maths-free cage puzzle that's quick to learn, start with Suguru. Both are pure-logic puzzles with a single solution, so it comes down to whether you want the Sudoku rules and sums or not.