In the quick look for The Tomorrow Children and in the recent podcast, the team complained about the sliding block puzzles, saying how much they hate them and how hard they found them. I figure some people in the GB community might have the same trouble, so as a public service: here's a very simple guide to solving every solvable sliding block puzzle ever:

gkhan's foolproof guide to sliding block puzzles

Solve the first row and first column first, then the second row and second column, etc.

That's the general stragegy. Think about it: if you have a 5x5 puzzle, solving the first row and first column reduces the problem to a 4x4 puzzle. You will never have to touch that row and column again. You then keep doing that, solving smaller and smaller puzzles until you're done.

To solve the first row, line up all numbers in their proper place except the last two

So, in a 5x5 puzzle, put the 1, 2, and 3 blocks in their proper place. You should have no problem doing this, you wont mess up previous positions.

Put the next number in the top right corner, then the next number below it

See how the 1, 2, and 3 blocks are lined up? The next number (4), is put in the top right corner, and the number after that (5) is below it. What is currently in the "4 spot" (a 9 in this example) doesn't matter.

This shouldn't be too difficult. Move the 4 first, then the 5. If you find that they get "tangled up" in each other, move the 5 away a block or two first so you can properly position the 4.

(incidentally, I'm using screenshots from this site for the images)

Now just "rotate in" the remaining two numbers

Move your empty place into the spot where the 4 should end up, then move right and down. Congratulations, you've solved the first row.

Do the same for the first column

Now, move the blocks in the first 3 numbers in the first column to their proper position, then put the last two in the bottom left, similar to how you solved the first line. Notice that the 1, 6, and 11 are in their right spots, and the 16 (the next number) is in the bottom corner and the 21 is right after that.

Then, just "rotate in" the numbers (from this position, by moving down and right), just like you did with the first line.

This "rotate in" trick is the key, here. You'll never have trouble getting the first numbers of a row or a column right, but the last two can get "entangled" up in each other and be put in the wrong order. But if you do this, you'll get it right, every time.

Now you have a 4x4 puzzle. Proceed in the same manner.

Your first column and first row have been set, you should never touch them again. You don't need to. Imagine that the first row and first column are just "gone" or something. Just do the "first line" of this new puzzle (which is the second line of the whole puzzle) in the same way: line up all the numbers except the last two, put them in the corner, and "rotate in".

Solve the column in the same way as before, line up all numbers except the last two, then "rotate in" the last two.

Now you have a 3x3 puzzle

You get the idea. Line up the first number in the first row, then rotate in the next two, do the same for the column

Now you have a 2x2 puzzle

Just rotate clockwise or anti-clockwise enough times, and the puzzle will be solved. Good work, you!

Congratulations! You can now solve every solvable sliding block puzzle ever!

You don't need to follow this guide religiously. If you really want to, you can solve the first two lines before you tackle the columns, for instance. It also wont give you the optimal solution, but you wont get that any way. This way it ALWAYS works out, if the puzzle is solvable at all.

Sliding block puzzles still suck, though

Once you learn this trick, sliding block puzzles goes from incredibly annoying to basically trivial. You can solve every sliding block puzzle like this, and it requires almost no "thinking", it's entirely mechanical. Unlike, say, Sudoku or Picross, no sliding block puzzle will ever be "interesting" or "fun to solve", because you already know the trick to how to do it. Instead, they become incredibly tedious, because you know exactly what you need to do, and now you just have to execute everything, which is incredibly boring.

Game developers: never put sliding block puzzles in your games. Either they're annoyingly hard if you don't know how to solve them, or they're trivial and tedious if you do.

This guide is incredible and I just implemented it in Resident Evil 4. Great job!

Thanks, this is a huge help and well written as well!

That's a great guide, but still... Fuck sliding block puzzles.

This is great, thanks. I've managed to get good at solving these, but I never had a formula.

I will say that sliding block puzzles like this can be okay, as long as there's some kind of interesting take on the concept. For example, there's a part in Doorways: Holy Mountains of Flesh where the tiles in the sliding block puzzle correspond to your surrounding rooms.

Wow wow wow, this is great.

Wow, that's such a simple solution which never occurred to me. I actually want to try some sliding block puzzles now.

gkhan: a true hero.

Here is my alternate guide to solving every sliding block puzzle ever:

Throw it in the trash where it belongs.

Thank you! I solved a few on the site you linked in minutes and it felt AMAZING!

I thought I spotted a flaw, but I suppose for non-square puzzles you can just solve individual lines until it becomes square. So, yeah, neat! I can't say I enjoyed these before but they tend not to pop up in the kinds of games I play anyway.

There's always more difficult variations though...

Oh, another interesting take on this is from the Wallace and Gromit game (spoilers):

Parents used to get us 5*5 puzzles things that release candy when solved. As kid a found that simplest way is to just go line by line from top to the bottom.

I've always liked these kind of puzzles.

I seemed to be a natural at sliding block puzzles as a kid. I didn't know the techniques I was using, but damn they worked.

As an adult I'm terrible at them, i'll remember this guide if I get stuck in future

WHERE THE FUCK WERE YOU WHEN ONIMUSHA CAME OUT? YOU COULD HAVE SAVED SAMONOSUKE FROM DROWNING SO MANY TIMES. T.T

Great guide man, these fucking things finally make sense to me. This shit was the bane of me as a kid, it was the one type of common logic puzzle I couldnt figure out on my own. :(((((

+1 I also don't like this type of puzzle and this guide is great!

@gkhan Can I just say that your guide is great but your Prokhor Zakharov avatar is greater?

May actually try children of tomorrow now. Thanks for the guide. I always kept the cheat sheet for the slide puzzle in resi 4 but maybe I can get rid of it now.

Aww, you guys, thanks! I hadn't looked at this thread after it dropped off the first page of the forums without any replies, had no idea anyone had seen it. I thought it had just vanished into the internet ether, but then suddenly 3 months later Vinny is tweeting about it and I come back and see a bunch of thank-you comments I had missed! Made my day!

I know that pain, dawg.

This is why I love this site, I can count on people regularly recognizing a Prohkor Zakharov avatar. Lets go build some god-damn Locusts of Chiron and fuck up Sister Miriam!

You know, that's really true. People in my life don't tell me that enough. I should get better people...

Yup.

Well done.

Yup. The Resident Evil 4 puzzle recently made me realize I have zero strategy whatsoever for solving these. This is helpful!

Just saw Vinny's tweet about this and tried it out myself. This is awesome. I'm gonna keep practicing so I have this down for the next game that comes along with such a puzzle. (Also like your final note there.)

Hey there, I know this post is old but if anyone is looking at it, I need some help. At the end of the puzzle, when there is just a 2x2 left to solve I'm getting stuck with two blocks that need to swap positions with each other but I have no idea how to do that, so if someone could help me out (Especially because this says its a fool-proof guide, sooooooooo) it would be really appreciated.

@qazzaqqwert: You need to break the 3x3 you completed to get your 2x2 pieces into place. I don't remember exactly how without looking at it, but keep reassembling the 3x3 until the inner layer looks like it will fall in place.

As the person who wrote the guide: I think someone is having a spot of fun with you! See how I wrote in the header "every SOLVABLE sliding block puzzle". The reason is that they are not all solvable. If you just plop down tiles randomly, there's only a 50/50 chance that the puzzle is solvable. In particular, if you literally just swap two pieces lying next to each other with the empty square in the bottom right, the puzzle is not solvable (which sounds like the situation you're in). This is Sam Lloyd's famous 15-puzzle. For a full description of why this is, this page provides a nice description (there's a little bit of math required, but nothing too bad).

If you've gotten to the last 2x2, and just moving the empty square around doesn't solve it, then you've either made a mistake earlier (i.e. some other pieces are out of place), or the puzzle is not solvable. If you want to make sure, check that page I linked, count the number of inversions in your puzzle, and check the condition they describe.

The way I solve sliding puzzles is by going row by row instead of row and column by row and column.

@gkhan: I have never known how to solve these, but you have just taught me something. Thank you!

I recently had the urge to play through RE4 again, so I'm bookmarking this for said purpose.

Also, it blew my mind how obvious the general tactic used here is - yet I likely never would have divined it myself. Thanks, duder.

@gkhan Thanks, this is really good. I started doing these when I was small, so I usually get there in the end but I didn't really consider that there might be a technique beyond the "fix each row" approach.

I love that this dumb guide of mine is periodically unearthed from the depths of the giant bomb forum archive. I just realized it's probably because this page is now the number 1 search result for "solving sliding block puzzles", which is a real weird honor!

I mean... that's the technique, more or less! I usually alternate rows and columns, but... yeah. The tricky part is that most people don't figure out the "rotate in" trick to solve the rows/columns. If you don't figure that part out explicitly, these puzzles can be real tough. For instance, in the first row of a 5x5 puzzle, if you line up 1,2,3 and 4 in the right places, it basically gets impossible to put the 5 in correctly. If you try, you mess up the 4. If you try to put that one in, you mess up the 3 or the 5 and then suddenly the entire puzzle is a mess. The trick is realizing that you should rotate in BOTH the 4 and the 5 at once, not separately.

@gkhan: I know this is now super old, but I still have to thank you for this. Because of your guide I finally understand these stupid puzzles that have perplexed me my whole life. Just completed the Retro Achievements for Winky the Little Bear thanks to you.

I admit i do search for this thread whenever i encounter a sliding block puzzle.

This thread is completely new to me and as someone that despises block puzzles, holy shit what a feeling.