Sans

**Sans** (/sænz/) is the brother of Papyrus and a major character in *Undertale*. He first appears in the forest after the protagonist exits the Ruins. He serves as a supporting character in the Neutral and True Pacifist routes and as the final boss and heroic antagonist in a Genocide Route.

## Profile

### Appearance

Sans appears as a short, paunchy skeleton with a wide toothy smirk, large eye sockets. He wears an unzipped blue hoodie, a white tank-top, black shorts with white lining, and a pair of salmon-colored slippers. He has white pupils that disappear when he is serious or angered. When Sans uses telekinesis, his left eye flashes light blue and yellow, the colors for patience and justice, and his right pupil disappears.

### Personality

Sans is laid back and flippant, often sleeping on the job and taking breaks. His laziness is a combination of fatalism and apathy. He wonders if his indolence stems from his knowledge that any progress he makes will be erased when the timeline resets. Conversely, he suggests that this knowledge could be "a poor excuse for being lazy."

Though Sans is usually agreeable, he becomes eerily serious at particular moments. He is also observant; Sans reads the protagonist's expressions and can often tell when they have already done certain tasks. He enjoys making skeleton-related puns and the fact that he performs at MTT Resort hints that he may be a talented comedian. He enjoys science fiction and loves to drink ketchup. He also hates making promises.

Sans may have a scientific background. Evidence includes the quantum physics book, workshop, his relationship to Alphys, affinity for science, and his timeline research.

### Abilities

Sans can quickly travel or teleport using what he calls "shortcuts."

In combat, he uses "Gaster Blasters," devices that resemble a skull, to shoot large beams. Sans excels in combat and fights with unique abilities that include: KR, applying directional forces directly upon the protagonist's SOUL, and attacking the protagonist in their own selection menus.

Because of his "research," he has knowledge of timelines and the SAVE function. However, he does not retain his memories when the protagonist loads a SAVE, and he cannot use the SAVE function. His awareness of time travel makes him scrupulous, and he recognizes when the protagonist is behaving unusually. Sans reads the protagonist's expression and determines if they have experienced events before and are repeating them. He also knows how much EXP the protagonist has and comments on it when judging them.

Sans also plays the trombone, though he is only seen playing it once while the protagonist is dating Papyrus. Papyrus also finds his "incidental music" annoying, implying that he has played many times before.

Like other characters, Sans is aware of when the game's code suffers bugs and calls the protagonist a "dirty hacker" if they achieve an impossible ending of a Neutral Route.

## Attacks

### Soul Modes

Sans starts by using red mode, but frequently switches the protagonist's SOUL between red and blue mode.

### Patterns

Sans often utilizes gravity to make his attacks require platforming skills, such as slamming the protagonist's SOUL against the walls of the bullet box and making the protagonist jump through gaps between bones and onto platforms. Sans uses regular and light blue attacks.

Sans immediately starts off the battle with his "strongest attack": an array of bones and blasters. He is the only enemy in the game that has the first turn rather than the protagonist, which can catch the unwary off-guard.

Eventually, Sans will offer mercy; if accepted, he covers the entire Bullet Board with bones until the protagonist's HP is drained to 0. This results in the famous Game Over screen that is only seen on this occasion. If this happens, death is inevitable, although if the save file is hacked to get unlimited health, Sans will continue to shrug, but the bones will disappear and the game cannot progress without save reloading or other hacks.

After that, he starts to employ randomly cobbled attacks made of "bone stabs", "Gaster Blasters", and "bone slides". He will also start to use "Gaster Blasters" more frequently and aggressively, and will start using vertical "bone slides" rather than just the horizontal variation he uses during the first half. After a while, he does his biggest attack, which is a massive army of Gaster Blasters.

## Strategy

To progress the fight, the protagonist must keep attacking Sans, as checking reveals that he cannot dodge forever; performing any other action besides FIGHT will not progress the battle, as his dialogue will not appear or advance. Also, skipping/missing the attacks will not progress the battle either.

After getting past his mercy offer, the fight then includes Sans constantly flickering the screen as he transitions through his attacks, uses his beams more often, and even attacks the protagonist as they navigate the menu (though menu attacks will only deplete the HP to 1). After enough turns, Sans will then perform an attack lasting roughly 40 seconds, launching some attacks shown previously at the protagonist, including a bevy of "Gaster Blasters", a large array of bones, and many slams against the Bullet Board's walls.

Once the protagonist survives his final attack, Sans will use his "special attack," which cannot do damage to the protagonist. Sans abstains from attacking and stalls his turn out indefinitely, preventing the protagonist from accessing the menu in hopes of the protagonist becoming bored as time passes.

If one tries to move to the left before Sans falls asleep, he will wake up as his eye flashes blue/yellow, and the SOUL will be teleported back to the center of the bullet board. After several minutes and dialogue, Sans will eventually fall asleep, allowing the protagonist to push the Bullet Board towards the FIGHT button.

After pressing it, Sans will wake up and dodge the first attack, only to be ambushed and struck down with another automatically-performed attack, instantly finishing Sans off for good. Unlike most enemies, however, he starts to leak a red fluid of some sort (which is hypothesized to be injected determination, ketchup, or even blood), then limps offscreen before dying, raising the protagonist's LOVE to 20 and HP to 99.

## Mechanics

Sans dodges attacks (thus negating his need for high defense or health) and removes the protagonist's health slowly further through KR, although more INV can slow this down. The latter statement means that his attacks (true to his flavor text when Checking him) deal 1 damage *per frame* the protagonist's SOUL is colliding with them, allowing Sans to inflict weak hits at such a rapid rate (up to 30 times per second without extra INV) that it adds up to draining the protagonist's entire HP within a few seconds. Some attacks involve platforms the protagonist's SOUL can rest upon safely. From his false plea for the protagonist to stop fighting onwards, Sans will also attack the protagonist in the action menu.