# Samurai Sudoku rules

I’ve been asked a few times to post some Samurai sudoku solving tips. Well – there aren’t any special tips that apply exclusively to Samurai. Standard Sudoku rules apply, but to make things clear for newcomers, I’d like to give a brief set of instructions.

#### Rules of Samurai Sudoku

1. Each Samurai Sudoku puzzle consists of 5 overlapping classic 9×9 Sudoku sub-puzzles. 2. Each 9×9 sub-puzzle must be solved according to the rules of Sudoku: each row, column and 3×3 box must contain all digits from 1 to 9; therefore, digits cannot be repeated. 3. Each Samurai Sudoku puzzle has one solution only.

Warnings: 1. DO NOT ATTEMPT to completely solve each sub-puzzle as an individual puzzle! 2. Each 9×9 sub-puzzle when solved individually could have more than one solution. 3. Never resort to guessing my puzzles can be solved using deduction logic.

#### Solving suggestions

1. Work on the puzzle as a whole. 2. Start with one sub-puzzle and solve as many cells as you can, until you can’t go further (do not guess!) 3. Move on to the next sub-puzzle. Use clues from the previous sub-puzzle. 4. Repeat step 2 for that sub-puzzle. 5. Keep repeating steps 2-3-4 until you solve the whole puzzle! 6. Do not start with the center sub-puzzle. They usually have fewer clues than other sub-puzzles. Usual classic Sudoku techniques are required to solve these puzzles: naked and hidden singles, naked and hidden subsets (pairs, triplets etc) and “row/column and box interactions”. For the hardest of puzzles X-Wing and Swordfish techniques might be needed.

1. Merry
Posted February 13, 2006 at 11:18 pm | Permalink

For newcomers — what are naked and hidden singles, naked and hidden subsets, etc, as mentioned above? Or where can I find out where they are — your help only tells you how to solve sudoku x puzzles, not regular ones (or samarai).

2. Ankora
Posted February 28, 2006 at 5:36 pm | Permalink

3. LaKena
Posted April 17, 2006 at 5:15 am | Permalink

I’m gonna work out this Sunday’s solution. I love a logical challenge on paper.

4. Terry
Posted April 18, 2006 at 5:45 pm | Permalink

I have been looking for about an hour now and can not find the solution to the 4-14-2006 Express Lookout Weekend Samurai Sudoku puzzle. My friend has 3 of the 5 puzzles done and has an error. I was going to help her find it. Can you tell me where the solution is located. Thanks!

5. Posted April 19, 2006 at 1:37 am | Permalink

Terry, I’m sorry but we only post solutions for the puzzles printed in The Post. We don’t post those from The Express. That’s the deal we made.

6. Cristina
Posted May 2, 2006 at 8:47 pm | Permalink

Dear DJape,

I lost my solution to the online samuri game from April 25. Is it possible for me to get the solution again?

Thank you,
Cristina

7. Posted May 4, 2006 at 1:54 am | Permalink

My brother Mom and i have just started these puzzles and are going crazy to try and finish them. they are so addicting and fun!!!!!!!!

8. Mary
Posted August 24, 2006 at 12:34 pm | Permalink

I would like to get a blank copy of the puzzle that is posted in the sunday post.

9. Posted August 24, 2006 at 1:22 pm | Permalink

Hi Mary,

Sorry, we cannot show puzzles from The Washington Post on our website. You can get a blank Samurai grid here: http://www.djape.net/download/images/samuraigrid.png

Download it, print it and copy the given numbers from the puzzle that you have.

Good luck!

🙂

10. Rich
Posted September 26, 2006 at 9:22 am | Permalink

Thanx 4 the rules/tips that you listed. They give more than any other site has listed of any kind.It may not be needed for everyone but in the Samuarai the clues give some more help. Thanx. Rich

11. Chris
Posted December 18, 2006 at 10:20 pm | Permalink

Hello. I am solving this Sunday’s (12/17) Samurai Sudoku puzzle in The Washington Post and i was wondering, is it possible to solve it without using the X-Wing or Swordfish Techniques? (it says its a 2 out of 5). Also is whats printed the post Samurai Sudoku X or Killer? And what exactly is the difference between the the three versions?

12. Chris
Posted December 20, 2006 at 4:06 am | Permalink

I would still like an answer to my first question. Also at the top you said “Well – there arenâ€™t any special tips that apply exclusively to Samurai.” well i believe i have found one that does. Well it would work for any large puzzle that overlaps in at least one nonet. It has to do with how numbers repeat because of the overlap. I can explain in detail if you want.

13. Posted January 25, 2007 at 7:07 pm | Permalink

Hi Chris,

Sorry for responding this late…

Yes, 12/17 Samurai puzzle from The Post can be solved without X-Wing and/or Swordfish.

It requires either naked/hidden subsets OR row/column and nonet interactions. There are a couple of approaches to solving it.

In fact, about one half of the puzzle can be solved using only naked/hidden singles.

– Samurai Sudoku puzzles are those that you can see in The Post every Sunday.
– Samurai X puzzles are similar but with one additional rule: each diagonal (there are 10 diagonals in each Samurai puzzle) must contain all numbers from 1-9, just as any row/column/nonet.
– Killer Samurai: those are completely different. You don’t have any given numbers, instead you have “cages” (fences) with a number which indicates the sum of the numbers within a cage. Don’t worry about Killer Samurai – if you are interested, you should first practice Killer Sudoku which you can find every day on my “Daily Killer” page: http://www.djape.net/killer-sudoku/

If you have any further questions it is best to ask them in the forum: http://www.djape.net/sudoku/forum

Have fun!

Djape 🙂

• Vanie
Posted December 14, 2017 at 4:48 pm | Permalink

What does X-wing and swordfish mean and how do they work

14. Norbert Dee
Posted February 26, 2007 at 4:39 am | Permalink

Can you explain or point me to a reference to explain what are naked/hidden singles or subsets. I am a new player. Thanks

15. Posted February 26, 2007 at 10:57 am | Permalink

Norbert Dee, you can find that in the classic sudoku techniques section: http://www.djape.net/?p=157

djape

16. Emma Lee
Posted July 16, 2007 at 12:37 am | Permalink

Hello,
I was out of town on June 17, 2007.
Is there any way I can get a copy of the samurai sudoku from the Washington
Post?

Thank you,

Emma Lee

17. Posted July 16, 2007 at 1:52 pm | Permalink

Hi Emma Lee,

Unfortunately, the answer is no. The deal with The Washington Post is to show only solutions for the puzzles and not the puzzles themselves. This is simply because those puzzles have been designed exclusively for the readers of The Post and if I showed them on my site they would be available to anyone.

I hope you find some other puzzle on my site that you find interesting.

18. steve
Posted August 9, 2007 at 7:07 am | Permalink

I do the sudoku alot with 5 others from work. I found a Samurai sudoku and made copies for the others i do them with.. we all are still working on the same Samuri sudoku for the past two weeks and none of us have been able to figure it out yet.. There ready to kill me.. HELP.. ( this samuri sudoku is only a 2 out of 5 )

19. Royalty
Posted August 16, 2007 at 8:19 pm | Permalink

Hi, i’m a newcomer to this website but not to sudoku…..but i just started working on samurai sudoku puzzles…..and from what i seen so far from this website, i see there are a lot of techniques that i never knew of, when i was doing regular sudoku puzzles…i was just wondering if you had a page just explaining all the different types of techniques and their names that you can use?

20. Janet
Posted August 25, 2007 at 10:51 pm | Permalink

Hi,

I am a samurai wizard and never spend more than a leasurely hour on anything under a 4 but the last 2 puzzles (August 18, and todays, August 25) have gotten me at a total stand still with nothing more to do than start guessing and they are ‘2’. I never guess. Is someone else writing these?

Thanks …

21. Posted August 25, 2007 at 11:46 pm | Permalink

Hi Janet,

No, it’s still me creating these puzzles. 🙂 I don’t think the difficulty of the two puzzles you mention is any different from other puzzles.

Where did you get stuck? No guessing is required, I can assure of that. Perhaps it was just your bad day? 🙂

Good luck!

Dj.

22. Posted September 15, 2007 at 6:54 pm | Permalink

I am curious to know whether a “5” rating means it’s harder than the lower ratings. I have also found that a 4 rating appears easier than a 2 rating. Can anyone tell me which is the hardest rating?

23. Posted September 16, 2007 at 3:02 pm | Permalink

Manny, yes, a higher number means that the puzzle is more difficult. However, the difficulty of a puzzle is a very personal thing, to some people some puzzles are easier than other, while some people would find the opposite.

Do not pay too much attention to the indicated difficulty. Try to solve the puzzle and enjoy doing it! 🙂

Good luck.

24. Peter M. Smith
Posted January 21, 2008 at 9:27 pm | Permalink

Dear Sir,

While attempting to solve the Samurai Sudoku (Wash. Post, Sunday 1/20/2008) I seemed to have arrived at non-unique solutions). Four of the 9×9 puzzles solve uniquely and are consistent amongst themselves. The fifth 9×9 puzzle (bottom right seems to have multiple solutions) with two non-unique rectangles for the digit pairs 54 & 89.

My solution for the this lower right puzzle is with x=54, y=89

192 3xx 876
853 671 429
746 y2y 135
427 583 691
368 192 547
519 467 283
634 y1y 752
285 736 914
971 2xx 368

FYI, the center puzzle solved as
861 234 579
523 789 416
479 156 238
634 527 981
952 861 347
718 943 625
386 475 192
147 692 853
295 318 746

Could you please comment on the uniqueness of this Samurai puzzle,

Thank You

Peter M. Smith

25. Posted January 22, 2008 at 10:44 am | Permalink

Dear Peter, the problem is with your solution of the center puzzle. You have two 6s in the last column of the center puzzle, which, of course, is against the rules.

26. Tiara
Posted January 23, 2008 at 3:04 am | Permalink

Hey… so I was looking for something to check my one of my sub-puzzle things.. so is there anyplace I can go to check my work?

27. claudia
Posted April 7, 2008 at 9:22 pm | Permalink

After trying to solve one of these since january, I was finally able to solve the 3/30/08 edition in the wash Post. after working on it for over a week! I have a hard time understanding the written explainations on tips to solve. I am reminded of the Louis Armstrong Quote about What is jazz? “If you have to ask you’ll never know? That’s how I feel about x wing and sword fish,and naked triples. I think i need a live chat version of solving tips:) I just don’t understand the explainations.! anyway, I’m off to try my luck with the 4/7 edition!!!

28. Posted April 7, 2008 at 10:20 pm | Permalink

Claudia, X-Wing and Swordfish techniques are never needed in the puzzles that are published in The Washington Post and/or Express.

Naked/hidden triplets might occasionally come about and they can be difficult to spot, but with a little practice you should be fine.

The best advice I can give – practice those advanced techniques (such as naked/hidden subsets) on regular Sudoku puzzles and then move on to the Samurai puzzles.

Good luck and let us know how you’re doing! 🙂

29. Becky Rice
Posted June 30, 2008 at 3:05 am | Permalink

How do you determine the difficulty, example 0-5? Have you ever had a 0? Is 5 the most difficult?

30. Dennis F.
Posted September 30, 2008 at 2:05 pm | Permalink

Has anyone solved the puzzle from Wash. Post 9/28/08. I am stuck on the top right boxes. What did you get?

31. Posted September 30, 2008 at 2:59 pm | Permalink

Dennis, you can find the solution on the http://www.djape.net/solutions/ solutions page.

32. Alex
Posted December 2, 2008 at 10:42 pm | Permalink

ok so i have to do a samurai sudoku for extra credit in school. but i dont get the directions AT ALL!!! i need help to solve it!!

33. Posted December 3, 2008 at 2:30 am | Permalink

Alex, the best place to get an advice is in the forum: http://www.djape.net/sudoku/forum

34. Lynette Maria Entzian
Posted June 16, 2009 at 2:47 am | Permalink

I am looking for the solution for the Samurai Sudoku puzzle from the Washington Post for Sunday May 10, 2009. Do you know how I can find it?

Thanks,
Lynette

35. Posted June 16, 2009 at 7:48 am | Permalink

Hi Lynette,

The solution you are looking for is in the archive:
http://www.djape.net/gallery.php?file=Washington%20Post%20Solutions%202009/May/

Hope you’ll find it.

36. Ivan Soto
Posted April 9, 2011 at 11:15 pm | Permalink

The samurai sudoku published in The Washington Post of April 10, 2011 has no solution. Why bother to publish sudokus with such poor quality control?
-9—4-6—–5-1—8-
-678–4——-3–961-
—-6———–7—-
35—2–1—4–6—92
—1-62——-27-1—
4–7—9—–6—5–3
—-9—-6-7—-3—-
4–7—9—–6—5–3
—-9—-6-7—-3—-
–9–3—3-9—5–9–
-4—8———9—6-
——4–7-6–9——
——–8—2——–
——2–4-8–6——
-7—9———5—7-
–1–7—1-4—8–4–
—-2—-5-3—-4—-
6–7—8—–4—3–2
—3-56——-81-2—
93—8–4—9–4—87
—-3———–3—-
-459–1——-6–875-
-8—1-6—–8-6—2-

37. Posted April 12, 2011 at 3:57 am | Permalink

Ivan, you will have to elaborate on that comment.

It has never happened that a puzzle I published had anything but a unique solution. So, if you claim that this one doesn’t, I ask you to have a look at the archive where there is a solution to this puzzle.

http://www.djape.net/gallery.php?file=Washington%20Post/

Cheers,
Djape

38. Ivan Soto
Posted April 15, 2011 at 10:54 am | Permalink

Well, I can’t reproduce the solution I had. I no longer have the puzzle as originally published by the Washington Post and the copy I received from you, Djape, does have a solution. Either I overlooked something when I went through my solution or else the copy I received from you does not exactly replicate the published puzzle.

The benefit of my doubt should go to the publishing procedure and so I withdraw the comment about poor quality control.

39. Carl Knoettner
Posted April 17, 2011 at 3:26 am | Permalink

How to Play instructions “Don’t focus on completely one grid at a time.” should read “Don’t focus on completing one grid at a time.”

(Please just send me an email. You don’t need to publish it on the website. I just wanted to make to Washington Post directions better.)

40. Bil Greene
Posted January 29, 2012 at 3:19 pm | Permalink

It would make your puzzles easier to work with if you could put up a grid so that we could print if off. That would hopefully give us a bigger space in which to put our possible numbers in the squares and when our squares got to messy we could then print off a new one.

Thanks

• Posted January 30, 2012 at 2:26 am | Permalink

Bil, thank you for your comment.

If you need a blank grid for Samurai Sudoku or Diagonal Sudoku (which is also good for Killer Sudoku), you can find all of them here: blank grids.

41. Kenneth Laun
Posted December 1, 2012 at 1:30 pm | Permalink

There appears (at least to me) to be a second solution to the Sunday, 11-25 puzzle from the Washington Post. All changes are in the center three columns of the center section. Below the 5-7-1, use 9-6-8, next 4-2-3, then all the same as you had until the penultimate line of three which would be 6-3-9 and the last of 2-8-4. Ken Laun 703-978-1390 or see below.

• Posted December 2, 2012 at 1:36 am | Permalink

123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789123123456789
123456789123123456789
123456789123123456789
123456789
123456789
123456789
123456789123123456789
123456789123123456789
123456789123123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789
123456789 123456789

Then I will tell you if you are right or wrong. 🙂

42. Neil A Spangler
Posted May 29, 2017 at 3:57 pm | Permalink

Folks, I seriously question your grading system. For instance, your 4’s and 5’s are really no problem but a 3 gives e
me fits. What’s going on here?

43. Gent
Posted May 30, 2018 at 11:50 am | Permalink

OK, first Question….Why am I the only entry for 2018?
Next….I enjoy Sudoku in all the local papers and rags.
I was visiting an in-law in D.C. when I ran across a Samurai Sudoku in the Post (5/20/18)..1st time I’ve seen an SS, so I took it on. Hit a wall on the lower left puzzle, all the rest went fine. What am I missing?
Answer this question, is this how the lower left box in the center puzzle reads?
341
627
895
If these are correct, then you got me, I’m stumped