## 20x20 - 8x8 sum sudoku

For fans of Killer Sudoku, Samurai Sudoku and other variants

### 20x20 - 8x8 sum sudoku

Hi all, I would like to request a feedback for this concept I've been working on.
This is another variant of sudoku I've been playing around; though current puzzles are not too hard, but it feels fun and solid enough. The premise of the game is simple: You are given an 8x8 grid, which you need to fill in with numbers between 1,2,3,4,6,7,8,9 (no 5). The rest is similar with regular sudoku: no repeating the same numbers across, vertically or in any surrounding cells... However there's one twist: each 2x2 group must add up to exactly 20.

A solved 20x20 puzzle will look like this:

To try out the puzzle, I've made a web version of the game and uploaded a few puzzles; you can head over here to try: https://dwidasa-2e37f.web.app/
If you find the idea interesting, help me make it better and give me some feedbacks
bhimz

Posts: 16
Joined: 16 November 2015

### Re: 20x20 - 8x8 sum sudoku

Here is an example generated with my solver. Medium difficulty, (locked set + x-wings or chains)
Code: Select all
`. . . 4 . . . .. . . 6 . . 1 9. . . . . . . 89 . 1 . . . . .. 7 . . . . 6 .. . . . . 6 . .. . . . 1 . 4 2. 4 . . 3 . . .`

On your app which does not work in my browser following puzzle has multiple solutions:
Code: Select all
`0126370007080962269748300400027902008000083026071904000003020000`

Found some more with multiple solutions..others are not minimal and very easy.

Level 4 can be reduced to this, difficulty: very hard.
Code: Select all
`. . 6 . . 1 . .. . . . . 4 . .. . 1 . . 6 8 .9 . . . . 2 1 .. . . 9 . . . .. 7 2 . . . . .. 9 . 7 . . . .. . . . . . 2 .`
creint

Posts: 298
Joined: 20 January 2018

### Re: 20x20 - 8x8 sum sudoku

creint wrote:Here is an example generated with my solver. Medium difficulty, (locked set + x-wings or chains)
Code: Select all
`. . . 4 . . . .. . . 6 . . 1 9. . . . . . . 89 . 1 . . . . .. 7 . . . . 6 .. . . . . 6 . .. . . . 1 . 4 2. 4 . . 3 . . .`

Thanks for the feedback creint, will try to work on it a bit more. Anyway I don't think your puzzle is vaild.. one of the rules is "the same number can not repeat in the same row, column or surrounding column", hence the two 6's on the bottom right corner cannot exists.
bhimz

Posts: 16
Joined: 16 November 2015

### Re: 20x20 - 8x8 sum sudoku

I overlooked that anti-king rule.