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Variants

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Wow, if you've made it this far im impressed! using all the techniques ive given you up to this point you should be able to solve any "Normal" Sudoku. If you arent satisfied yet and want more and you havent had any time to research any variant sudokus yet, or youre hoping for a couple more obscure tricks then you've come to the right place. There is many different variations of sudokus and many different rules that can be added to drastically change how one needs to approach a puzzle or think about what new logic a new ruleset will let you explore. here ill talk about some of those variations and maybe even a technique to go along. Many times variation sudokus will have multiple variant rules so its important to know as many tricks as possible for many different rules so you're always ready

Killer Sukdoku

Killer sudoki is a variant sudoku that adds the concept of cages, cages are represented on a grid by a dotted line encasing one or more cells and contains a number in the upper left corner of the cage. the number in the corner of the cage represents the total sum of digits inside the cage. Thats right we've added addition to our rules! an important thing to remember when doing a killer sudoku is all rows, columns and boxes in a normal sudoku add up to a total of 45 (the digits 1-9 being added together =45). We can use this fact to help deduce the location of some digits as ill show below

a sudoku grid showing cages represented on a grid by a dotted line encasing one or more cells — In the bottom row of this Sukdoku, the cages totals add up to 24 + 6 = 30. if we use the fact that a row should add up to 45 and subtract our 30 given to us. we will know the first box, bottom row should add up to 15 (45-30 =15). we can then subtract our 4 and 5 from what we have left and we will know the highlighted cell is 6 (15 - 4 - 5 = 6)

Arrows

Arrow sudoku works similar to killer sudoku (its just addition) however, often times an arrow will begin completely blank. An "arrow" is represented in two parts. One part is the bulb which is a circle inside of cell connected to an arrow, that number is the total of all the numbers along an arrow. and connected to the bulb is the arrow which is a line with the bulb on one end and an arrow at the other. Each cell covered by the line/arrow adds together to equal the number in the bulb.

Renban Lines

Renban Lines are a rule in sudoku marked on the grid by a purple line that passes through atleast 2 different cells(Not to be confused with green German Whisper lines). Digits along a Renban line must be consecative but not in any order. for instance you could have 3 4 2 along a line but not 1 2 4.

German Whispers

German whisper Lines are a variation rule marked by green lines the pass therough atlease 2 cells. Cells along a German whisper line must be atleast +/-5 digits. this has many implications to it, firstly the number 5 could never go on a german whisper line because no number is atleast +/-5. You can also use german whisper lines to try and predict numbers based on if its a low or a high value which might be useful. This is fairly simply since any number below 5 on a german whisper line, can only be next to other numbers GREATER that 5 on the whisper line.

sudoku grid showing a green german whisper line, the box is empty other wise — German Whisper Lines can never have a 5 on it, in fact this whole box can be filled out. see if you can figure it out

Phistomefel Ring

A Phistomefel Ring is a realtivey new discovery about sudokus. Discoverd by puzzle German creator "Fistafel" the technique had been showcased on puzzles in the popular youtube series Cracking the Cryptic and Puzzle fourms like Puzzle Masters Germany. The discussion on how to spot or use a Phistomefel Ring is long, so please see the video below where the Phistomefel ring is discussed.

Did you get through all of that? Wow I cant believe it, give yourself a round of applause on me!