Barrier

The Barrier is a strong magical force in Mount Ebott. It is locked by SOUL power and separates the Underground from the Surface. The barrier is located behind the Throne Room in New Home, and appears to be a silent, endless room transiting from white to black. Somewhere within the floor are seven vials, six containing the six human SOULs.
Due to the War, seven human magicians conjured it to protect humanity and keep monsters trapped in the Underground. Anything, including humans, can fall through the barrier and enter the Underground's Ruins, where Toriel generally finds them. However, only a being with the SOULs of a human and a monster can pass through the barrier and exit the Underground. The barrier can be broken, though it requires a huge amount of power equal to seven human SOULs, or six human SOULs and the SOULs of monsterkind. Only eight humans have fallen through the barrier: the first human, the six humans, whose SOULs were collected by Asgore, and the protagonist.
When the barrier shatters, it is depicted as being a before splitting apart.
Beyond the barrier is a dark room with a sunlit patch of grass, and a purple arch depicting the Delta Rune.
== Trivia ==
* In the console versions of Undertale, the selected border is disabled when the protagonist enters the barrier.
* The protagonist only enters barrier and the sunlit patch of grass room in the Neutral and True Pacifist routes.
** In console versions, the border is disabled in the Neutral Route for both areas. In True Pacifist Route, the border is enabled in the sunlit patch of grass room.
* At the end of a Neutral Route, the protagonist appears in the dark room with the sunlit grass, though the barrier was not broken. It is unclear if Flowey's brief influence over SAVEs is the cause.
* Depending on the route, there is a slight difference when the protagonist nears and crosses the Delta Rune arch. However, the screen always fades to white once they cross through it:
** In the Netural Route, they cross through the arch without a prompt. After the white screen, it abruptly turns black, and the Undertale title and "By Toby Fox" appears. This is similar to when the protagonist goes through Home's Delta Rune arch to enter Snowdin Forest.
** In the True Pacifist Route, the protagonist is stopped by a brief narration before being given a prompt to leave or not. After the white screen, it slowly fades in to a scene of the protagonist and their friends looking at the sunrise.
* When the barrier breaks, the narration text is different. It lacks the typical dialogue soundbyte, and the letters have additional spacing between them as the words are displayed at a slow pace.
* The post barrier location resembles the Start Menu and two areas in the Ruins where Flowey appears. It is the area nearby the bed of Golden Flowers, and near the exit door of the Ruins, nearby Toriel's Home.
== References ==
de:Barriere
es:Barrera
fi:Este
fr:Barrière
ja:Barrier
pl:‎Bariera
ru:Барьер
uk:Бар'єр
zh:屏障
pt-br:Barreira
Category:Plot Mechanics