# Futoshiki

**4.3**/5 (82 votes)

When I was in elementary school, I had a teacher that taught me a good mnemonic device for remembering the symbols for greater than and less than. She said to imagine a crocodile (or a hungry bird or a Pac-Man or something) in between the two numbers. The crocobirdman would always open its mouth and eat the larger number. Little did I know back then that I would later find myself facing grids of over one hundred of these symbols in varying patterns. In Futoshiki, a Sudoku-like number puzzle, your goal is to fill in the grid using a slew of inequality symbols as your only hints.

Like in Sudoku puzzles, Futoshiki puzzles have one of each digit in every row and column. You will often come across puzzles that have no starting digits, so you must rely on the inequality clues to fill in the grid. For example, if you find a chain of boxes that are greater than the next box in line, you could assume the positions of higher and lower digits in that chain. To input a number, you can either click and hold a box then drag down to the number you want, or use the [arrow] keys to move the yellow outline to the box you want and press the number key on your keyboard.

**Analysis:** For such an engaging puzzle, it's somewhat disappointing that the presentation for Futoshiki is a little bit lacking. As with Kakuro, another logic puzzle offering from the developer, ATK Solutions, the graphics are rather simple and the music is somewhat cheesy and might get grating after a bit (pun unintended). It would be easy to pass this game off as slightly amateurish if you didn't spend enough time with it.

But if you take the time to sit down and play a few puzzles, you'll realize one thing rather quickly: These puzzles can be deviously difficult. With so few clues to help you out, you'll most likely start to solve these puzzles by eliminating many possibilities before you can confidently fill in a single cell. Fortunately, you can use the pencil feature to write in potential answers, or even print out puzzles if you prefer to work them out on paper.

If you're willing to look past the less-than-appealing design, Futoshiki is still a clever puzzle that should please any heavy-duty logic puzzler. If you think you're ready for something that's perhaps a bit trickier than the standard Sudoku but still a smidge easier than crocobirdman wrangling, be sure to give Futoshiki a try. The challenge may be *greater than* you think!

I recognize that music! The title theme is

Japanese Cartoon Song, which is also the main theme for Free World Group'sPuzzle Freak 2.The "puzzle complete" song is familiar, too; it sounds like a remix of a certain riff from

Sonic the Hedgehog 2's Casino Night Zone (1P version).I'd post links, but I've probably gone to too much trouble to drag this discussion off-topic as is.

0(0 votes)The whole Pac-Man thing never clicked with me. It wasn't until freshman year of high school that I got a teacher that told it to me in a way that made sense.

The Less-than sign looks like an L if you turn it just a little.

The Greater-than sight looks like a G if you had a curving line to it, from the bottom end.

Never had problems after that.

0(0 votes)I'm using Safari (Mac OS), and the page loads, but there's just an empty space where the game should be... I really do wanna check this out though, I dig these kinds of games.

Anyone else have this problem?

[Also using Mac OS, and I cannot reproduce your problem in Safari (tried v5.0 and just updated to v5.0.1). I don't have any extensions installed, though, so you might try disabling any you have. Sounds like it could be an extensions conflict. -Jay]0(0 votes)I like Simon Tatham's version. Plus you can play it in a Java applet or download it for 'most anything.

Jellybones, I can't duplicate your problem in Safari or in Chrome.

[I removed the link. Please respect our "No link dropping" policy. Without it the site would attract much more spam than it does already. Thank you for understanding. -Jay]0(0 votes)I just updated to 5.0.1 and it works now. Not sure what the problem was, maybe something to do with outdated plugin software? Anywho, it's all good now.

0(0 votes)Jay: does linking to the jayisgames archives count as linkdropping? Just to be safe, I won't link it, but the Simon Tatham version can be found in the February 23, 2008 edition of Weekend Download. (Worth mentioning, in fact, because this week's "Mobile Monday" featured an Android port of the games, and in following the links I discovered that Tatham had (a) added a handful of games since being featured in 2008, and (b) put Java applets of them up.)

[You may link freely to the JIG archives, or mention names of games that are similar. However, let's also be considerate about the game this review and comment thread are about and keep the discussion on topic. If you're going to say "I like this other game instead" at least tell us why and give a comparison as it relates to the game being discussed. Thanks. :) -Jay]0(0 votes)I don't know if I'm missing some obvious strategy, but boy is the easy puzzle harder than I expected. I'm slowly going through all the possibilities in all the squares and eliminating impossible answers, hoping I can get somewhere.

0(0 votes)w00t, I solved easy :3 It was tough, but very doable, once I just dove into it. I have a solid strategy now.

0(0 votes)It's been over 2 hours, but I just got through medium.

Here's a hint:

Don't worry about the inequalities until you really need to narrow down the numbers. Think of it as sudoku, with a few extra parameters to help you along.

Great way to pass the time, I gotta say.

0(0 votes)Neat puzzle. They've also got a version of Kakuro, another math-based puzzle I like. Like this one, the graphics and interface are sorely lacking, but it's the best I've been able to find online.

0(0 votes)We reviewed that version of Kakuro here at JIG:

http://jayisgames.com/archives/2007/07/kakuro.php

I'm surprised Artbegotti didn't mention it or link to it in the review. (I guess I'll add it.)

0(0 votes)I found it easiest in medium to fill in 7 at all the "high" points and 1 at all the "low" points and then work from there, getting rid of inconsistencies the way through.

0(0 votes)Actually, I can't believe I forgot it either... Thanks to keith for bringing it up, thanks to Jay for adding it in!

0(0 votes)Great fun, for certain values of 'fun', but be warned that the 9x9 'Hard' level can take a *long* time to solve. There may be strategies I've missed to speed it up but it took me several hours of constant intense number crunching.

I can't prove it but it seems like the time taken to solve rises exponentially with the grid size.

Essential strategy for harder puzzles:

If you have a group of n cells in a row or column where you have eliminated all but n or fewer possibilities, you can eliminate those possibilities from the rest of the row. Eg, if you have two cells with just '12' remaining, you can eliminate 1 and 2 from the possibilities in the rest of that row or column. If you have three cells with '123', '123', '123', you can do the same, and this also applies if some 1s, 2s or 3s are missing from your candidates (eg '12', '13', '123'). This extrapolates up, and on the 9x9 grid you may be doing this with groups of five or six cells.

0(0 votes)Whoa, the 'hard' level is dastardly. Just for reference, I stopped playing any online sudoku about two years ago, because even the hardest puzzles were too easy for me. Nice to have a logic/number game that actually challenges me again :)

0(0 votes)Oh, unfortunately, I do get a bug in Chrome 5.0 on Ubuntu 10.4 where if I navigate away from the tab the game is in, it freezes and I can't do anything until I reload.

0(0 votes)I

likethis. :-)(I too grew tired of Sudoku. This is a wonderful variant.)

0(0 votes)@jellybones: It did that for me, too - the first few seconds. Then it showed up. Not sure if you just didn't wait long enough or what, but it started loading after a few seconds. (In Firefox on Mac, anyway.)

0(0 votes)Hi Jay/Art, this was a good week. Several new jobs this week, and then logon to see this reviewed! Really do enjoy this flash game stuff. I will be adding new puzzles and eventually some new smaller hard (crocopac-wrangle style hard ones)! Thanks for the review guys, much appreciate it. -Anthony (ATK)

0(0 votes)My brain hurts, but I just can't stop :S Everytime I discover a new approach, the game manages to put me in a stalemate again. Great stuff!

0(0 votes):O You guys who got tired of Fiendish Sudoku makes me feel really not smart (haha). I appreciate the skills and brain power I've honed from Sudoku because I feel them getting an exercise when I play Futoshi. But I would REALLY appreciate a magic trick for playing Futoshiki. I wouldn't dare touch Sudoku until I read the simple elimination of threes. Suddenly, Sudoku wasn't about trial and error; it became logical. I need the confidence to start locking down numbers on Futoshi (and I'm talking about Easy level here), not rely on faith that "I'd get it eventually". Eh, maybe I'm thinkin too much and I simply need to get used to it? (I'm reading up on this AB elimination strategy.) So if anyone else has any nifty tricks, let me know!

0(0 votes)There's several different approaches possible ("N" = maximum value):

Greater/less than allThis only works if all operators are visible: go into pencil mode and enter a "1" in every field that is less than each neigbouring field, and an "N" in every field that is greater than each of its neighbours. Check each row; if there's only 1 "N" in it, this field has to be the max value and all "N"s in the corresponding column can be deleted. Do the same for the "N"s in each column (deleting copies from the rows), then repeat these 2 tricks for all "1"s. You should now have the locations of all "N"s and "1"s.

Start again from the top, but now use all "2"s (less than all neighbours except "1"s) and "N-1" (greater than all neighbours except "N").

'Greater than' seriesFind a series of fields where each field is greater than the next. In pencil mode, fill in "N" in the greatest field, "N-1" in the next, and so forth. In the last field, add all numbers down to "1". Since each field has to be greater than the next, back up through the series and add all numbers down to "2" in the second field, "3" in the third, etc - the reason being 2nd field could never contain a "1", since this prevents it from being larger than the first, and so forth.

Note that a 'less than' series is exactly the same, you just read it the other way round.

Y Combinations of Y numbersIf, in any single row or column, you have a number of Y identical fields containing Y numbers, you can cross these numbers off from all other fields in the same row/column. E.g. if you have 3 fields where the only possibilities are 1, 3 or 6, there's no way any of the other fields in the column can use these numbers as this would make it impossible to fill out the fields in question.

(This is a refinement of motty's tip - thanks by the way, I neede that one)

Only in combining them will you be able to crunch the harder ones. If anybody else has suggestions, I'm all ears - there's still quite some puzzles in which I eventually get stuck.

0(0 votes)Realized I forgot this addition to the 3rd theory - I actually couldn't sleep trying to make a proper formula out of it, but an example will probably have to do:

If - in the same row or column - you have X combinations of 2 possibilities, where all possibilities listed in these X fields are X+1 different ones, and you have 1 field containing all these X+1 options, you can remove them from all other fields in the same row/column. (Cripes, I think the cold light of dawn actually made it possible...).

E.g. if you have combinations 13, 36 and 136, the first can be either "1", in which case you revert to the third theory in the previous post(being left with two fields of 36), or a "3", in which case the 2nd automatically becomes "6" and the 3rd "1". 12, 24, 47 and 1247 works the same way (resulting in either 2+4+7+1 or 1 in the 1st field reverting to the previous example).

@Tenny: you should just dive in and see how far you can swim, by the way. If you like these kinds of puzzles, most of the satisfaction is in finding out the ways in which to solve them - even more than actually solving them... So give it a try and see what you can come up with.

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