#undertale duodecimal

I think the monsters use base-12. (I’m going to go ahead and explain base-12 since it’s not common knowledge, if you already know then you can skip the next paragraph!) Basically, base-12 (or duodecimal) is a numerical system in which twelve is the first double-digit number. Counting in duodecimal would look like this: 1, 2, 3, 4, 5, 6, 7, 8, 9, X, Ε, 10 With X being equal to ten, Ε equal to to eleven, and 10 equal to twelve. The values are still the same, but the characters used to represent them change. This is admittedly a pretty sucky explanation but if anyone is genuinely curious I can try to do better lol ANYWAY my friend initially brought this up; she immediately paused after getting this dialogue:

[Image Description: Two text boxes indicate Papyrus’s dialogue. The first reads “I’m just a dozen away...” and the second says “from a double digit follower count!”] If monsters are using duodecimal, this would make a lot more sense! Instead of having -2 followers like he would have in decimal (or 111 if you want to get SUPER nit-picky), he would just have... 0. I think this is probably the most convinving piece of evidence in our favor. Of course it could just be some fun dialogue Toby through in as a joke, but overanalysis is fun so. I’m not stopping there. Next I noticed the in-game year:

[Image Description: A screencap from the opening sequence. Pictured is a mountain, labelled Mt. Ebbot 201X] So, initially, I believed 201X was meant to indicate some year between 2010 and 2019, with X replacing the last number. BUT if you consider that X is a character marking the value of ten in duodecimal, the year becomes 3478 in decimal (aka base-10, the number system we use). Now if the year had only been mentioned in the opening sequence, it would be a lot easier to play off as an unknown, but it’s written on a calendar in Asgore’s house!

[Image Description: A screencap from inside Asgore’s house. Frisk is inspecting a bookshelf. The text reads “There’s an old calendar here from the end of 201X. A date is circled on it.”]

You can’t really make a calendar for a nondescript year (unless he’s got just... a nine year calendar?) so it would actually make more sense, in my opinion, for 201X to indicate an exact year in duodecimal than a range of years in decimal. Those are my really hard-hitters, but I also think it’s cool to think about WHY monsters would use duodecimal. The reason humans use base-10 is because we typically have 10 fingers. It would be easier for a person with 10 fingers, 10 ‘digits,’ to use a mathematical system based around the number 10. But as far as I can tell, monsters don’t have 10 fingers. Granted, this could be more related to art-style, but the coincidences are stacking up at this point, right? Look at these sprites:

[Image Description: Toriel’s death sprite. She’s holding one hand against her chest while the other rests on the floor.}

[Image Description: Mettaton’s first battle sprite. He holds a microphone in one hand. His other hand is outsretched.] I dug through a lot of sprites trying to count fingers, but these two stood out the most: They both appear to have 4 digits on each hand. If we are to assume that the monsters have been sealed underground for a while, it would make sense for them to eventually convert to a numerical system that fit them better, right? So they would probably want to choose a base divisible by the number of fingers they have on a hand. It just so happens that 12 is divisible by 4.  Sure, they could also use another base like 16, but Papyrus’s initial comment and the fact that X is used instead of A have me leaning towards 12.

TL;DR the monster’s numerical system revolves around the number 12 instead of 10.