A perspective-changing CPU theory

So, I’ve got a theory. And, if it’s true, it’s a theory that would change our perspective on not just amiibo training, but Super Smash Bros. Ultimate’s AI as a whole. It’s a time-consuming test, so I can’t say for sure, but it’s still something to discuss regardless. Here’s the premise: yes, amiibo learn from you. We knew that. But what if I told you the CPU learns from you, too? Now, again, it’s tough to say for sure, but I’ve gathered some evidence that might support this. Take this post with a grain of salt and let’s get going.

Please note that this theory was originally researched by Leaf. The topic itself was explored prior by the competitive amiibo community. Do not repost, rewrite, or otherwise reproduce this work without direct permission from staff. This includes (but is not limited to) blog or website posts, images, and videos. Thank you for your patience.



Those of you who aren’t so familiar with Ultimate’s AI will need a bit of “base knowledge” before going on to read our theory. Here’s what we know for sure about personalities. As you know, a Figure Player can inherit one of several personalities through training or Spirits. Though personalities don’t matter much in training a tournament-ready FP, each one can be loosely categorized by one. So, then, what does a personality actually consist of? Values. A lot of values.

Within an amiibo’s chip is an assortment of numbers that go up and down based on what it learns in matches. There are values for how often it jumps, runs, walks, grabs, taunts, edgeguards, and meteor smashes, among others. And there are values for each of it moves and how often it uses them. There are even values for aggression, avoidance, reacting, “reading” opponents, and defensiveness. The game looks at these individual values and, through a process we don’t know about, labels them with a personality. Two “Aggressive” personality Figure Players could act completely differently despite having the same label. You can read more about personalities right here.



Super Smash Bros. Ultimate has the strongest and most adaptable AI in the series. It’s even better than it was in 4, where CPUs had a one-frame reaction time and could perfect shield just about everything. So here’s our theory for Ultimate: CPUs have personalities too! …Except you can’t see them. I think that CPUs can learn from you, whether by scanning your play or analyzing matches (I don’t know which one). Figure Players have a default AI that resembles – but is not related to – the CPU’s AI. I think that, since amiibo are technically CPUs, that training them might actually affect the playstyle of CPU fighters.

So, then, evidence. It’s thought that each Nintendo Switch profile saves some sort of CPU record to Ultimate’s save data, and that when you make a new user, you start with a blank slate of sorts. We know that user profiles are a factor in amiibo training thanks to one of Nintendo’s in-game tips: “The first time an FP battles with a fighter or FP, it gains more experience than usual. It’ll also learn more if it is used on a friend’s Nintendo Switch”. Now, this quote could be totally incorrect. It wouldn’t be the first time. But if that last part is true, the game would need to compare the amiibo’s owner to the user profile playing Super Smash Bros. Ultimate. But, then, is it profile-specific or console-specific? That part is difficult to test.


User Profiles

I’ve done more than a spot of testing with this theory, and here’s how I went about it. First, I made a new user profile and tested out the Link CPU right away. I noticed it used its arrow a lot, which is not something it did on the previous profile. It seemed to underuse its side special, forward tilt, up air, and forward air. A Link amiibo on the previous profile was trained to use these moves, and the corresponding CPU fighter appeared to use them too.

Another interesting tidbit is that a Level 1 amiibo generally mimics habits of Figure Players you’ve already trained on that profile. For example, if I were to train a Mario amiibo to spam its forward smash, the second Mario amiibo I trained on that profile would be more inclined to use forward smash (even if the move value was set to 0) despite being at an early level.

Pichu is another character of note, and a somewhat divisive one at that. Some trainers report Pichu’s AI taking a liking to its Thunder move, while others report they cannot get Pichu to use Thunder at all. I tried setting a Pichu amiibo’s Thunder priority to maximum, but it still wouldn’t use it. But then we had a trainer send us a replay of their Pichu amiibo using Thunder. We inspected the amiibo’s Thunder priority, and it was nowhere close to maximum. How would this make sense, then, if this theory wasn’t true?

Of course, there’s the possibility of placebo (or placiibo, in this case), so we can’t quite confirm the theory based on this information alone. I’ve got more evidence down below, but if you’d like to test this yourself, feel free to! Make a new user profile, open up Smash, and fight a CPU character. Keep an eye out for moves the CPU is not using. After a few matches, pull out an amiibo of the same character and train it to use the moves the CPU didn’t attack with. Fight the CPU again, and you might notice it has started to use them a little bit! It won’t be an incredible difference, but it will be a tangible one. Maybe.


Spirits & Arenas

Another question that I’ve been unable to answer up until now is why Battle Arenas seem to mess with amiibo AI. Many trainers have reported noticeable differences when playing against their FP online, and if our theory of CPU learning is true, this makes sense. If you don’t know this already, most of our online tournaments involve sending a file of your amiibo to a tournament host, who then plays the match on their system as if they actually had the figurine with them. Thing is, most tournament hosts train amiibo themselves, which means (if the theory is true) their CPUs have learned from them. Because our guides are the most read on the internet, and talk about similar training philosophies, many of these trainers might train their amiibo in very similar ways — and thus might have similar CPUs. 

Recall that CPUs cannot be used in Battle Arenas in any way, shape, or form. In fact, Figure Players are the only AI-controlled characters that can be used online. If two trainers connect to a Battle Arena with one amiibo each, whose console data does the arena use? It’s possible it can’t decide, and instead defaults to a blank slate, which results in noticeable playstyle changes. Another important thing to note is that amiibo can’t learn from Battle Arenas… but they can learn from Journeys. We aren’t sure what this means, though.

But if this theory is true, it means Battle Arenas are the most neutral tournament settings possible. That being said, if you were to run the same match on two different consoles, the result is almost always the same. At the end of the day, your training will carry over regardless of the setting; both Battle Arenas and submission tournaments count. And the moves and movements you teach them are a hundred times more important than the default AI (which is what we’re saying learns from you).

Remember World of Light? You probably do, and you probably remember that certain opponents were programmed to take certain actions. Some of them favored a specific move, some of them were more attracted to items, and some of them would run away and avoid combat. These are all settings that exist in an amiibo’s data files, so we know that at least a few personality values are inherited by CPU players, too. Once you know how personalities work, you could probably recreate any of these Spirit battles by teaching an amiibo to do the same thing. In regular battles, CPU fighters behave quite differently on a game-by-game basis, but Spirit battles often play out the same due to the CPU’s specific programming.



So, what does it matter if CPUs learn from you? Well, it doesn’t change amiibo training much, but it does give us some insight as to how CPUs and amiibo fighters may have been programmed. It also means that Battle Arenas have a bit more value than they did before I researched this theory; whereas trainers thought they were “messing up” their amiibo, they might actually be revealing them instead. If your amiibo can win a bunch of matches in a Battle Arena, you know it’s ready for tournaments!

In the meantime, we’ll continue hosting submission tournaments as we’ve always been, but we’re going to try to place a higher focus on Battle Arena competitions. Ideally, we’d like to split them up half-and-half so that trainers have the opportunity to enter both kinds of tours. In the meantime, feel free to join our Discord server to keep an eye out for the latest tournament listings. Thanks so much for reading, and until next time!

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