Logic Masters Deutschland e.V.

---

PUZZLE:

---

---

RULES:

---

Normal Sudoku rules apply.

• Kropki: White dots separate two cells containing digits of consecutive value; Black dots separate two cells where one is double the value of the other [ratio of 1:2] (not all dots are given).

---

MODIFIER:

---

• Vampire: There are 9 Vampire cells contained within the grid comprised of a set of the digits from 1-to-9. Each row, column and box contains exactly one Vampire cell. There are nine 9 Prey cells contained within the grid following the same rules as the Vampire cells. A cell may have only one of these roles.

for Kropki values
Prey cells contribute no value (0).
Vampire cells contribute the sum of the digits in the Vampire cell and Prey cell within the same box.

---

INTRODUCTION:

---

I've been enjoying both setting and solving these puzzles. People seem a bit hesitant about the Vampire constraint but once you get into it the logic quickly becomes familiar (I'm sure we all felt that way about the more common constraints upon first sight, as well!).

I could see it becoming more and more mainstream and I sincerely hope it does - as I said, these puzzles a blast. This is likely one of the better places to start exploring the constraint, in terms of difficulty, or you may want to start with Mad-Tyas's puzzle (listed below).

Here are some puzzles from other setters using the same constraint:
"Vampires" by Mad-Tyas
"Vampires' Secrets" by lepton

An example puzzle will follow to better illustrate the rules.

Have fun!

---

Solve in f-puzzles!
Solve in SudokuPad!

---

---

     

Watch Scojo Solves

---