201X 

A fictional year in the 2010s. Used in Undertale, OK K.O. and whatever else the creators don't bother choosing an actual year for. See also Year X on TV Tropes.

They could just say the year is 201X, maybe that's the way they say years on this world. Or maybe "X" could be substituted for anything, so it could be 2015, if you're playing the game next year it could be 2016 (the year after that), up until like, 2019. It's kind of cool. - jacksepticeye

201X by BlazeNinja22 January 17, 2025

Rule 201X 

If it exists, there is a Megalovania of it.

Alternative Name: Rule 100 (Megalovania is the 100th song in the Undertale OST)
Origin: A parody of Rule 34 (If it exists, there is porn of it.). 201X is the year that the events of Undertale take place.

1: Hey, do you know if there are any Power Rangers Megalovanias out there?
2: Rule 201X.

Rule 201X by Shugunou February 10, 2022