A game created by Toby Fox, where you star as a human in an underground society full of monsters. You can spare, or kill your enemies, which teaches people you don't have to murder everyone!

There are three routes.

Pacifist is where you spare everyone and no one dies at all, (Which is honestly the best ending.)
Genocide is where you murder everyone in the underground, which results in a lot more sobbing and feels if you play it after pacifist.
Neutral is where you killed a few and spared most, so like the middle man.
Girl: OMG! Have you heard of Undertale?! It's SUCH a good game!
Girl 2: Never heard of it,
Girl: BITCH! GET OVER HERE! *Tackles*
by OnyxQV December 24, 2015
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An RPG created by Toby 'Radiation' Fox and a few others. Became popular at the end of 2015 due to a Kickstarter a few years earlier and a lot of famous Youtubers (most notably Markiplier, Jackscepticeye and Steam Train) doing Let's Plays of the game.
"Have you played Undertale yet, dude? It's such a fun game."
"No, man, don't have the funds. I'll watch a Let's Play until I got enough money to buy it."
by Firework917 December 24, 2015
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an RPG made by Toby Fox in which you are a human who falls down into a mountain, and you work your way out and it breaks the fourth wall in gaming and probably has very complex coding
Friend 1: Oh, man, you gotta try Undertale!
Friend 2: I hate that game!
Friend 1: But have you listened to THIS?
Friend 1: *plays MEGALOVANIA*
Friend 2: I still hate that game.
Friend 1: Have you played Undertale or even watched videos on it?
Friend 2: No.
Friend 1: YOU ARE GOING TO PLAY IT RIGHT NOW. SIT YOUR ASS DOWN AND PLAY.
by undertalefreak January 29, 2016
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I meh! game that is ok!
it is kinda ok!
fan:1: HEY
fan2: SHUT UP I'M PLAYING UNDERTALE!
by dj145 August 1, 2016
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A lovable RPG style game created by the brilliant Toby Fox.
"Hey have you played Undertale yet?" "Yes! I would totally smooch a ghost."
by Abbasanrox December 30, 2016
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An RPG game by indie developer Toby "Radiation" Fox. There are multiple paths to take, with even more endings. Be sure to do pacifist first, then neutral, and THEN genocide. Intricate plot line, clever jokes, it's got it all.
Hey, I just bought Undertale, and I'm gonna do genocide first!
You do that, I'll break your fucking neck.
by DaveStriderEatsFigs January 8, 2016
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