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Sample Puzzles!
Weekly Samurai X
Samurai X for Saturday, November 12 – this is the only place you can find these kind of Sudoku puzzles!
Basically, not only do you have to fight against 5 interconnected Sudokus, but you also need to be carefull about the diagonals: ALL diagonals in the puzzle must contain one occurrence of each 1-9 digit. The diagonals are marked in the puzzle so you wouldn’t forget about them.
Click on the puzzle thumbnail to access the puzzle.
Sequential Sudoku
Here is another very special Sudoku puzzle. In fact, it’s not only one puzzle but rather six of them, although you cannot solve them separately. Instead, you must solve them in the given sequence, because in order to solve a puzzle, you must copy a few numbers from the previous one. So, the first puzzle is a classic Sudoku, but then when you go to the second one, you check which cells are shaded in grey in the second puzzle and then copy the numbers from the 1st puzzle solution from the same spot. I hope it’s clear enough.
This is an existing concept, but I added a little twist to it. All six puzzles that you will find here have special “shapes” in them, so they really tell a little story. You must use your imagination, but here is my suggestion for this set:
1. You start with a game of chess
2. If you win, you get a chance to make a lot of money
3. So you set on a journey, but first, must find your way out of a maze
4. Which takes you to the stars
5. Where there’s stars, there’s black holes – you must avoid them
6. And finally, to return home you have to find an exit through a “wormhole”
Enough talk. Here is the puzzle
It’s a PDF file, so you need Acrobat Reader to view it and print it.
Let me know how you like it!
Subtraction combo
Udosuk, one of our visitors who is most active in giving hints for the puzzles we post here, has made a suggestion for a new solving technique for Killer Puzzles. He calls it “subtraction combo”. I’m posting his explanation here (slightly modified):
There it is. This is a good tip to remember if you’re solving a puzzle “offline”, without access to our site where you can use the calculator to find out which numbers could fill a cage.
I’m proposing a trick which I think many players already knew, but I’ll formalize it here anyway. I call it “subtraction comboâ€. For example, if you have a cage with the sum of 17, consisting of 4 cells and you narrow down the candidates to be 4 out of {2,3,4,5,6} which sum to 20. Since 20-17=3, 3 must be the odd candidate out, leaving {2,4,5,6}. Another example: a 3-cell 17-cage with possible values coming from {2,4,5,6,7}, which sum to 24. Since the 2 odd ones out must sum to 24-17=7, which can only be {2,5} here, we must have {4,6,7}. I find this technique quite useful in solving difficult killer puzzles, although it could only be applied after a cage is narrowed down to a few candidates. Hope other users will find it useful too! And if djape likes it you can describe this in details in your solving techniques column…
Posted in Solving tips
Tagged calculator, IQ, killer, solving technique, subtraction combo, technique
3 Responses
Weekly Samurai X
Samurai X for Saturday, November 05 – this is the only place you can find these kind of Sudoku puzzles!
Basically, not only do you have to fight against 5 interconnected Sudokus, but you also need to be carefull about the diagonals: ALL diagonals in the puzzle must contain one occurrence of each 1-9 digit. The diagonals are marked in the puzzle so you wouldn’t forget about them.
Click on the puzzle thumbnail to access the puzzle.
Daily & Weekly Puzzles
Since it seems that this week’s brain X was a tricky one, today I didn’t post an INSANE puzzle, but rather just an IQ. It’s still quite difficult – maybe even more difficult than the brain X.
I also posted a 4×4 classic Sudoku puzzle with another “shape” in it. It looks pretty I think. Don’t forget that Saturday is the day for Samurai X, our specialty. And I’m working on another type of Sudoku puzzles at the moment, which I hope to implement by next weekend, so you’ll get more special Sudokus available exclusively on www.djapedjape.com! Enjoy your weekend and get those brain cells working :).
Welcome new visitors!
Yesterday there was a post at blogs.guardian.co.uk about Killer Sudokus and a link to our site was posted. As a consequence, we’ve had some 600 referrals from that post within 12 hours (and overnight too)!
I’d like to welcome our new visitors and to suggest them to go through the previous messages posted here – there are some useful solving tips, explanations etc. One of the things that I should point out to them is that we post Killer AND Killer “X” puzzles, the later meaning that the diagonals must also be filled with all numbers from 1 to 9. Just to avoid any confusion and claims that our puzzles have multiple solutions…
Anyhow, I posted an “EASY” Killer puzzle after two tough puzzles posted in previous days. It’s good for practicing your “innies and outies”.
I also posted a classic Sudoku. As a consequence of a Sudoku book that I’ve been working on (more details on that in the next few days), I enhanced my software to create classic Sudoku puzzles with starting numbers placed in different “shapes” – this puzzle is an example. There are no extra rules for solving this, I think that it just look prettier this way.
Enjoy!
Posted in General
Tagged BOOK, Classic Sudoku, EASY, innie, INNIES, innies and outies, killer, killer sudoku, Killer Sudokus, outie, OUTIES, rules, solving tip, solving tips, sudoku book
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Comments
There were quite a few comments from our visitors, especially on the Daily Killer Sudoku page, which makes that and other pages load slow. Therefore, I have moved some of the old comments to this new category.
If you’d like to read what other people had to say about our puzzles you may find the old comment by clicking on the “comments” link below or here.
UPDATE (some 5 years later): I reopened the comments on all pages. Feel free to add your comments there, it means a lot to me!
Posted in General, Killer Sudoku
Tagged Daily Killer, Daily Killer Sudoku, FREE, killer, killer sudoku, UPDATE
969 Responses
Puzzle difficulty
First of all, I posted a Killer X puzzle rated THINKER for today. I would like to know how difficult you find this one.
Regarding the INSANE puzzle posted on Friday – I see that there has been a lot of discussion regarding it’s difficulty and the difficulty of some other puzzles posted last week. At the moment I’m rating puzzles depending on the number of different solving techniques that must be used, their relative difficulty (cage splitting is rated most difficult) and the number of times you must use each technique to solve the puzzle. For instance, the EASY puzzle posted on October 27 required only “innies/outies” and basic classic Sudoku techniques. Now, some “innies” are sometimes difficult to spot at a first glance, but it’s a basic technique which experienced solvers should’ve mastered by now. On the other hand, in addition to “innies/outies” the INSANE required cage splitting and some advanced Sudoku techniques (match/hidden subsets). I will have another look at rating puzzle difficulties and see if I can improve it. Perhaps I should rate “cage sums” more difficult for big cages (applying different combinations of possible cage sums).
Whatever the difficulty, I hope you are enjoying solving the puzzles. Difficulty is a somewhat personal issue – it depends a lot on which techniques you’ve mastered and which ones you’re still learning.
We’re still doing fine on the Top 50 Sudoku list. And we’re still the only site there posting daily Killer Sudokus (a couple of sites that claim they have Killers are actually just linking to us).
Posted in Killer Sudoku
Tagged Cage Splitting, Classic Sudoku, Daily Killer, Daily Killer Sudoku, EASY, hidden subsets, innie, INNIES, INSANE, IQ, killer, killer sudoku, Killer Sudokus, outie, OUTIES, solving technique, SUBSETS, technique, THINKER
3 Responses
Diagonal Samurai Sudoku
Samurai X for Saturday, October 29 – this is the only place you can find these kind of Sudoku puzzles!
Basically, not only do you have to fight against 5 interconnected Sudokus, but you also need to be carefull about the diagonals: ALL diagonals in the puzzle must contain one occurrence of each 1-9 digit. The diagonals are marked in the puzzle so you wouldn’t forget about them.
Click on the puzzle thumbnail to access the puzzle.
You Asked For It!
As promised, I just posted a puzzle with the rating that is currently in the lead in our poll. And that, apparently, is INSANE. This puzzle requires all Killer techniques + it requires some advanced classic Sudoku techniques (match subsets etc). It does not require trial and error! I hope someone will solve it without the aid of a computer. To be honest, I don’t plan to post many puzzles with this difficulty – it’s dangerous for your mental health!
I am surprised that according to the comments, people thought that yesterday’s puzzle wasn’t easy – all it requires for solving are innies/outies and nothing else. Although, if you haven’t practiced your outies you might find it more difficult. For instance, look at the first two rows. The sum of all cells in them must be 90. But the cage that belongs to nonet number 1 and is marked with 8 contains an outie for the first two rows! So you add up all the cages from the first two rows, find that their sum is 96 and therefore find that R3C3 must be 96-90 = 6.
There are 8 (but they solve 10 cells) innies/outies in yesterday’s puzzle altogether. If you don’t find all of them – you can’t solve the puzzle.
I also posted a 4×4 Classic Sudoku for the weekend. Don’t forget about tomorrow’s Saturday extra special – Samurai X – the only place on earth you can find them!
Posted in Samurai sudoku, Solving tips
Tagged Classic Sudoku, EASY, innie, INNIES, INSANE, IQ, killer, outie, OUTIES, samurai, SUBSETS, technique
12 Responses

