Sans is Ness

"Sans is Ness" is an ironic reference to "Game Theory: UNDERTALE - Sans's SECRET Identity!", a controversial episode of the YouTube series Game Theory by Internet personality MatPat about the supposed secret identity of the character Sans from the video game Undertale.

On the SiIvaGunner channel, this refers to a meme that encompasses multiple ideas, mainly the conflation of Sans and Ness, a general association between Undertale and , and general references to Game Theory.

Welcome to Game Theory!
Matthew Patrick, commonly known by the nickname MatPat, is the creator of several popular YouTube channels. His biggest channel is The Game Theorists, with its flagship web series, Game Theory. Co-created and narrated by MatPat himself, Game Theory showcases theories about various aspects of well-known video games, including speculations about hidden messages and subtexts allegedly present in video game lore. Since its debut on April 18, 2011, over 200 episodes of Game Theory have been published. The Game Theorists' YouTube channel has since amassed over ten million subscribers on YouTube, with the majority of Game Theory episodes having a like ratio of around 96 to 99 percent. Despite the popularity and success of Game Theory, both the show and MatPat were subject to heavy criticism during the mid-2010s. Aside from problems with specific theories, this also included things like padding videos, pandering to trending topics like , and MatPat's general attitude at the time. This would come to a head with the release of the episode that spawned the Sans is Ness meme, though in the years since it has died down somewhat in comparison to YouTubers with more serious scandals.

Can you imagine?
On February 9, 2016, an episode titled "Game Theory: UNDERTALE - Sans's SECRET Identity!" was uploaded to the Game Theorists channel. In this video, MatPat postulated that Sans from Undertale is Ness, the protagonist of the game EarthBound (or more specifically, the version of Ness from , a ROM hack of EarthBound created by Undertale creator Toby Fox). This episode was widely criticized and mocked for making far-fetched conclusions, having logical errors, and ignoring evidence that didn't support the theory. This episode currently has a lower than average like ratio and has since been frequently joked about online to the point where it has become a meme.

On February 4, 2017, nearly a year after the infamous theory, an episode titled "Game Theory: Who is W.D. Gaster? (Undertale)" was uploaded, explaining another theory about the identity of the character W.D. Gaster. At the start of the video, MatPat addresses criticisms of the Sans is Ness theory, arguing that it was just a fun exercise for him and that he never truly believed it himself nor expected it to be taken that seriously. Future mocking references to the Sans is Ness theory by MatPat would suggest that he agrees with the general consensus that the theory was a stretch.

But hey, that's just a theory!
On the SiIvaGunner channel, ironic references to MatPat's aforementioned theory have been placed in multiple rips. References to the Game Theory video itself can be found in quite a few rips, notably the first sentence spoken in the video: "Can you imagine a world where we're all represented by a font?" However, the majority of references to the Sans is Ness meme are indirect, involving things like:
 * Undertale tunes in EarthBound rips, and vice versa.
 * Undertale tunes segueing into EarthBound tunes, and vice versa, in medley rips.
 * The use of the Game Theory theme song ("Science Blaster" by SpellingPhailer), and excerpts from episodes of Game Theory.
 * The appearance of the meme personified, a Sans-Ness fusion referred to as Sens.