The New Sudoku Players' Forum

[ab]

I've never tried killer sudoku. However it struck me that there must be some redundancy in the puzzle. At the very least you could leave out the sum for one of the cages, which could eaily be deduced, but I'm sure you could leave out the sum of more than one cage in many puzzles. Have any puzzle compilers explored this?

[udosuk]

Have any puzzle compilers explored this?

Yes, many... More than you can imagine... Not only some cage sums can be omitted, even some of the cages themselves can be omitted...

Many players of Killer Sudoku puzzles on the web gather at this forum... In there you'll see about half of the puzzles compiled there have many "blank regions" (what we call "Zero Killer Sudoku" puzzles)...

Even in this particular place you can see some of these puzzles:

Mikejapan's Killer Albums

Jean-Christophe's (Non)Consecutive Zero Killer X

Richard S's Double Killer - 007

(There are extra rules in some of them...)

As early as 2005, Ms Miyuki Misawa, the "mother of Killer Sudoku", already posted puzzles with blank regions, and even puzzles with no cage sums, only inequality signs between cages...

http://www7a.biglobe.ne.jp/~sumnumberplace/22326860/

http://www7a.biglobe.ne.jp/~sumnumberplace/79790008/

[Pyrrhon]

Udosuk has said the most. I will only add the remark that in the Variant of the Year 2006 decision in this forum among the 12 best variants were 4 variants with restricted informations about the cages.

Pyrrhon

[ab]

thanks for the replies