How Baba Is You Makes Brain Busting Puzzles

Every December, I use my last video of the year to celebrate the most innovative and inventive game I played in the last 12 months. In previous years I’ve looked at the YouTube detective drama Her Story, the uncanny chatbot game Event[0], the serpent simulator Snake Pass, and the time-travelling murder mystery, Return of the Obra Dinn. These games have done things I’ve never seen before, and are impressive in both their idea and their execution.

They might not be the very best games of their respective years, but when it comes to fresh concepts done well, these are the games I would recommend. I certainly had lots of choices to pick from for 2019, like the combat-free role playing game Disco Elysium, the hilarious honk ‘em up Untitled Goose Game, the sci-fi archeology game Outer Wilds, and the other sci-fi archeology game, Heaven’s Vault. But this year, nothing quite beat the mind-melting puzzle game, Baba Is You.

Now, from first glance, this game looks pretty simple. You hop around a grid and push blocks - making it part of a sub genre of block-shoving puzzlers, all inspired by the Japanese game Sokoban. Here’s where things start getting strange, though: in each level, the rules of the game are written on screen as simple sentences. Like, “Baba Is You”, which means you control this funny white critter called Baba. Or “Wall Is Stop”, which means you can’t walk through walls.

“Rock Is Push” means you can shove rocks around, and “Flag Is Win” means touching the flag will finish the level. And then here’s the kicker: those rules are, themselves, blocks that can be pushed around - allowing you to break the logic that dictates the level at hand, and create entirely new gameplay by rewriting the rules. Remove the word “Stop” from “Wall Is Stop”, for example, and now you can waltz straight past walls.

Change “Flag Is Win” to “Rock Is Win”, and now the rock becomes your goal. Or push "Rock: into this sentence, and you switch the main character of the game into a tiny brown boulder. Cheeky. And thus begins a few hundred levels where the solution is never to simply reach the goal - but to rewrite the rules of the universe until you’re in a world where the goal is now reachable. It is infinitely intelligent and endlessly surprising.

It’s tough, but far from impossible, and practically every level is a revalatory experience with a satisfying aha! moment. And if you haven’t played it yet, now’s your time to pause the video, head to Steam or the Switch eShop, and get the game. I hope that you love it. When you’re done, remember to come back, and we’ll chat more about how the game builds its brain-busting puzzles Baba Is You is the brain-child of Finnish indie developer Arvi Teikari.

He told me over email back in April that he was inspired to make the game as part of the 2017 Nordic Game Jam. The jam’s theme was “Not There”, and the word “Not” made him think of logic operators in programming languages. Combine that with a block-pushing puzzle game like Snakebird or Stephen’s Sausage Roll, and this “resulted in a mental image of a block of ice not melting in hot lava due to the statement "Ice Is Not Melt”.

The scrappy, prototypical Baba Is You ended up winning that Game Jam, and the reaction was so positive that Teikari decided to take his underbaked jam game and turn it into a full fat release. Two years later, and the designer had about 219 ultra clever levels for players to work through. So how, exactly, is one of these Baba Is You levels made? To start, Teikari tries to think of an interesting interaction, or set-up that could come out of the game’s encyclopaedia of words and rules.

“Pull”, for example, could lead to a level where Keke needs to drag a key across a lake. A teleporter doesn’t have to just move objects, but could also be used to move around the rules themselves. And the word “Has”, could lend itself to a level where you drop a box every-time Keke dies, but that box immediately turns back into Keke. Bonkers. Speaking at the Gamelab conference in Barcelona this summer, Teikari said, “when I’ve got this idea of ‘hey, that would be cool to see in a level’, I try to figure out what kind of level do I have to build so that when the player is playing the level they have to use that interaction”.

And that’s where we get to the fascinating contradiction at the heart of Baba Is You. Because while this is a game that offers a seemingly infinite world of possibilities - its puzzles are largely defined by what you can’t do. Because while making an open ended puzzle game sounds great, it’s open to easy answers - like Scribblenauts, where half of the levels can be finished by writing in the word jetpack. So the designer’s job is actually to lock you in and force restrictions on you.

And in Baba Is You that’s achieved by the words that are and aren’t on screen, the way some sentences are pushed against walls or locked behind fences, and the claustrophobic grid that constricts your movements. With these restrictions in place, the designer can lock off easy answers - and force you to find the clever trick at the heart of the puzzle. Teikari calls this process reverse engineering - of essentially starting with the solution and then working backwards to throw up restrictions and make a puzzle that supports it.

As an example, take the level Baba Doesn’t Respond. In this level we play as Keke, and the solution is to use two belts to redirect a moving Baba. So how does the designer force this interaction? Let’s start by putting a wall and a locked door between Keke and the Flag. If we put a rule here like “Door Is Shut And Open”, we can just push the word “Shut” over and then go to the flag. But if we put a reed here, and make it so creating that first sentence simultaneously makes the rule “Reed Is Defeat”, we suddenly put Keke in a pickle - opening the door also denies access to that door.

Hm! Quite the catch! So, the player will hopefully realise that they need to have Keke be stood in this exact spot when the rule is triggered - and they just need to figure out how to move the sentence from afar. Answer: “Baba Is Move”. Now the level would be way too easy if we could just put Baba here, make “Baba Is Move”, and then walk to the right spot and wait for Baba to walk into the words. So, some restrictions are added.

This single hedge block means Baba only has a tiny run-up. And having “Move” be in the corner makes it impossible to, well, move, so the sentence “Baba Is Move” has to be made on the furthest left edge of the screen. These two things combine to make it impossible to make “Baba Is Move” and then walk to that all-important spot, because Baba will have already made the reed deadly by the time you get there. And thus, you must use these belts to create a much longer path for Baba to take, Chu Chu Rocket style, which will give you enough time to walk across the level before he triggers the sentence change.

Then it’s just a case of sprinkling on some pretty decoration, and putting in some other bits to restrict your movement or stop unintended solutions. Though, many of those are left in by the designer - provided they don’t make the real solution trivial. So as you can see, the solution to the puzzle is actually pretty simple. But by obfuscating the answer behind a sequence of problems, it creates this interesting phenomenon where Teikari is working backwards from the solution, locking up doors behind him as he gets to the starting conditions for the puzzle.

And then the player then moves in the opposite direction, opening each door in turn until they get to the solution. And by setting the stage up in this way, the player is actually somewhat lured towards the solution. Each level contains a number of tiny problems that render something impossible - forcing the player to find a different, more creative way to overcome the problem. These stumbling blocks then stack together, creating a pathway to the level’s solution.

Here’s how that looks in a favourite stage of mine: Tiny Pond. In this level, the word “Win” needs to be released from a pond. The water is tagged as “Shut”, and Baba is tagged as “Open”, which means you can walk into the water to unlock it and gain access - but this also destroys Baba. So, we’re going to need to try something else. We’ve got two other words: “Key” and “Flag”, and so we could make “Key Is Open”, but there’s no “Push” verb, meaning the key just sits there.

The only way to make it move is to write “Key Is You”, but we run into the same problem: you’re destroyed as soon as you touch the water. By now you should hopefully be thinking, “okay, maybe I can be both key and Baba at the same time, because when one dies, I can still control the other one”. But, sadly, there aren’t enough words to make that sentence work. However, the sequence of logical leaps have got you this far and there’s only one possible way forward now: if you make flag is key, you’ve got two keys.

And now if you have “Key Is You”, you can control both, sacrifice one to open a hole in the water, and use the remaining key to finish the stage. It’s really clever. The set-up for the stage walked us right into the central problem of the level: we need to be “Open”, but we also don’t want to disappear when we use ourselves. And so we’re in the perfect spot to try and figure out the actual solution - and go “aha!” when we get there.

If this was the first level that you played in this game, you would be - I think - completely stumped. But luckily, playing Baba Is You means constantly adding to an ever expanding knowledge base that grows with every stage you play. So Tiny Pond builds on the level Jelly Throne, where you control two characters at once. And Tiny Pond’s solution reappears in the stage Unreachable Shores, where you sacrifice one Keke, so the survivor can move forward.

But this sort of learning starts from the very beginning of the game. Baba Is You is a pretty complicated puzzler, after all, and there’s not a single tutorial in sight. Instead, the game’s first crop of puzzles all subtly and silently tell you how the game works through their solutions. So in Level 1, we’re stuck inside a tiny box. There’s only one way to get out and that’s to break the sentence “Wall Is Stop”, and make the wall no longer a solid object.

Then, we can make a sentence - “Flag Is Win” - to finish the level. That’s breaking and making sentences: the two most fundamental concepts of the game. Level 2 is the exact same stage as before but now everything is wrong. You play as a wall, the walls are made of flags, and Baba is nowhere to be found. This teaches players that nothing in the game has an intrinsic value: it’s only given purpose when part of a rule.

The game keeps this up throughout its first few stages, with solutions that clue us in to some fundamental concept we’ll definitely need to know later. Here, “Lava Is Push overrides” the rule “Lava Is Hot”. In this puzzle, we learn that we can create two sentences from the same “Is” block, by creating them in a cross. And the game will continue to teach new concepts and ideas throughout the adventure. Every time a new concept is introduced - like the operator “And” or the words “Open” and “Shut”, we’re treated to introductory puzzles that make these new mechanics crystal clear.

I asked Teikari how he went about making these introductory stages, and he said “If I exhaustively go through all the meaningful interactions between elements, eventually I get levels where the ‘trick’ is mostly just the basic functionality of a specific element in itself”. that can then be put at the beginning of the world, to act as a tutorial for the stages to come. While Baba Is You is full of puzzles that will make you feel stumped when you first play them, and make you feel smart when you solve them, Teikari’s real goal is to create moments of surprise and laughter.

YOUTUBER: [Laughter]. YOUTUBER: “There’s no rule saying ‘Wall Is Stop’. [Laughter] I was confining myself to this stupid little area and I didn’t need to.” That’s certainly one way it’s done - by playing with your expectations for how things work. In this level, for example, most players will assume they need to unlock the door. But actually they need to unlock the wall. There are also just bonkers rules that go way beyond the basic set-up.

“Empty” allows you to control or fill the empty space in each stage. “Make” lets you create a trail of objects when you move. “More” lets you duplicate keys until they fill every spot in the space. And just like the original idea for the game, “Not” allows you to flip rules on their head. Plus, in an attempt to make sure every single interaction is explored - a similar design philosophy as one used by Braid developer Jonathan Blow - Teikari has “Text” be a word, allowing you to manipulate the rules with other rules.

And by the time “Level” is introduced, you’re not only moving the entire screen around - but breaking out the stage and bouncing around the map screen in a mind-melting meta exploration of the game’s fundamental logic. There were more ideas that didn’t make the cut, of course. Teikari told me that “Stick”, which would make objects clump together, was removed because it created nightmare programming problems. And “Safe”, which would render an object invulnerable, was left on the cutting room floor because it was hazy, and uninteresting.

Not everything that made it into the game is a complete winner, if you ask me: a stage where you trap Keke under words and then push them away from the corner is awkward and confusing, and the word “Swap” is like “Tele” but not as cool. With 200-odd stages, though, there’s always going to be a few that don’t click for everyone. But Teikari points to an army of playtesters who gave feedback on stages, and discovered alternative solutions..

“I’m extremely thankful for how much testers have done for the game”, he says. That group of testers, it turns out, is a who’s-who of puzzle game wizards, and includes the designers behind Ending, A Good Snowman is Hard to Build, Pipe Push Paradise, Starseed Pilgrim, Minit, and The Witness. Baba Is You is a surprising, silly, and mind-bogglingly complex game. And it had every chance of becoming too difficult to grasp, too esoteric to understand, or too freeform to actually produce good puzzles.

But Arvi Teikari has proven himself as a master of puzzle design. He introduces the loopy logic of Baba Is You slowly and subtly, so everyone can understand it. With his reverse-engineering process, he buries a clever trick under layers of problems. But they’re never red herrings or pointless busy work - they’re about leading the player to the catch at the centre of the puzzle. And he’s more interested in surprises and silliness than rock-hard challenge, making for a game that will make you laugh more than it will make you frustrated.

It’s simply a really great puzzle game, built on a fresh concept that was executed perfectly. A no-brainer for this year’s final video. Hey, thank you so much for watching! I just wanted to take a moment to say thanks for all of your support in 2019. I’m really proud of the stuff I made and your support has meant the world. I’ve already got so many video ideas lined up for 2020 but it's time for a quick break. So I hope you'll have an amazing Christmas, and I’ll see you in the new year.