Chapter 1

For the demo that was originally titled DELTARUNE Chapter 1, see Deltarune Chapter 1&2.

Deltarune Chapter 1, subtitled The Beginning (JP: はじまり), is the first Chapter of Deltarune. It was released as a free demo for PC and Mac on October 31, 2018. It was later released for Nintendo Switch and PlayStation 4 on February 28, 2019. It was released for Nintendo Switch 2 and PlayStation 5 alongside Chapters 3 and 4 on June 5, 2025.

It is distributed alongside Chapter 2 as the free Deltarune Chapter 1&2 demo.

This Chapter is primarily set in Card Kingdom, a Dark World created in the school's unused classroom. Its antagonist is King, and its Shadow Crystal boss is Jevil.

Synopsis

The Chapter opens with the introduction, where the player is guided by the voice to create a vessel. Said vessel is then abruptly discarded following its completion, and the player is instead assigned to a fixed vessel: Kris, a human teenager who lives with their mother Toriel in Hometown.

At school, Kris is tasked to work with Susie, an intimidating reptilian monster, on a group project. During class, Susie and Kris are sent to retrieve chalk from the school's supply closet. However, they find out that the room is a pitch-black abyss. The door suddenly slams shut after they enter, and the floor gives way beneath them, leading the pair to fall into a mysterious Dark World.

Within it, the pair meet Ralsei, a kindly dark prince. He reveals that the three of them are the heroes of the legend of DELTA RUNE, destined to restore balance to light and dark by sealing Dark Fountains. During their adventure, they meet Lancer, a self-proclaimed "bad guy" determined to stop them from reaching his kingdom's Dark Fountain. Feeling undervalued, Susie leaves Kris and Ralsei for a time and teams up with Lancer. Susie's friendship with Lancer helps her become more compassionate.

After Kris and Ralsei defeat Susie and Lancer, they join the party. Susie telling Lancer that they will likely fight his father prompts the latter to betray them and lock them in Card Castle's underground prison. Susie escapes and fights Lancer, just to miss the last attack and promise him she and the party will not hurt his father. As such, the two become friends again.

Kris, Susie, and Ralsei battling King, as Chaos King plays

At Card Castle, Lancer's father King fights the party to prevent them from sealing the Eastern Fountain. However, he is ultimately defeated with Lancer's help. Afterward, Kris and Susie say their goodbyes to the Dark World and, via the power of Kris's SOUL, seal the Fountain.

Kris and Susie return to their world together, finding themselves in the unused classroom at the school, surrounded by toys and board games that represent the Dark World they ventured through and the characters they met. Kris and Susie agree to return to the Dark World the next day.

After Kris returns home and goes to bed, they shamble out of bed in the middle of the night, seemingly struggling to walk. They rip out their SOUL and throw it into a birdcage, before pulling out a knife and looking at the camera with a menacing smile as their eye glows red.

Chapter 1 characters

Main article: Category:Characters § Chapter 1

Main article: Boss § Chapter 1

Chapter continuation

Main article: Completion FILE § Chapter 1 Completion FILE

Chapter differences

Chapter 1 has a number of subtle alterations.

Cosmetic

If a SAVE File has not been created, the name "Kris" appears when checking any SAVE Point until it is overwritten with the player's chosen uppercase name from the introduction.

On PC versions, the window title varies depending on the player's current location. The text changes between uppercase letters to title casing.

• CONTACT: Appears in the File Select and introduction sequence before a Completion FILE is made.
• The Beginning: Appears while in Hometown at the start of the game.
• THE DARK: Appears while exploring the closet Dark World.
• The Return: Appears after sealing the Eastern Fountain and returning to the Light World.
• DELTARUNE Chapter 1: Appears after a Completion FILE has been made and before loading the prophecy scene.
• DELTARUNE: After completing the Chapter. Appears when the prophecy scene plays and onwards for this Chapter.

Gameplay

The SAVE is a replica of Undertale's, SAVE. It only permits SAVING in the chosen SAVE file slot.

The Recruits and Storage systems are not available.

The "TARGET" reticle during encounters appears, which indicates who the enemy is targeting.

There is no alternate route.

Release

Launch

On October 30, 2018, the UnderTale and UndertaleJP Twitter accounts had their names and avatars blanked out, and began to tweet cryptic messages. These messages are written in-character as the voice, using uppercase lettering in English and a mix of kanji and katakana in Japanese.

On October 31, 2018, remaining in-character, the UnderTale and UndertaleJP Twitter accounts tweeted out links to deltarune.com and deltarune.jp respectively (at the time, deltarune.jp redirected to deltarune.com). On October 31, 2018, the website contained a message written in-character as the voice and a download link for a file named "SURVEY_PROGRAM", with separate download links for PC and Mac, in English and Japanese. The in-character message also asked readers not to discuss the contents of the program for 24 hours. The SURVEY_PROGRAM is an installer for Deltarune Chapter 1.

On November 1, 2018 (24 hours after being posted), the Twitter accounts returned to normal, and deltarune.com was updated to have text written in a normal tone (rather than in-character). The DELTARUNE Chapter 1 OST was released on Bandcamp on the same day.

Nintendo Switch and PlayStation 4

On February 13, 2019, in a Nintendo Direct presentation, it was announced that Deltarune Chapter 1 would be released on Nintendo Switch via the Nintendo eShop for free on February 28, 2019.

On February 21, 2019, the official PlayStation Twitter account announced that Deltarune Chapter 1 would be released on PlayStation 4 on February 28, 2019 as well.

DELTARUNE Chapter 1&2

On September 15, 2021, to celebrate Undertale's sixth anniversary, Fangamer and Toby Fox livestreamed a modified version of Deltarune Chapter 1. At the end of the livestream, it was revealed that Deltarune Chapter 2 would be released on September 17, 2021 for Windows and Mac. Chapter 2 was released as a free demo together with Chapter 1, under the title Deltarune Chapter 1 & 2; it was distributed via Steam and itch.io (the first time either Chapter of Deltarune was distributed on these marketplaces).

On September 23, 2021, in a Nintendo Direct presentation, it was announced that Deltarune Chapter 2 would be released on Nintendo Switch as Deltarune Chapter 1&2 later that day. Deltarune Chapter 1&2 was also released on PlayStation 4 at the same time. On both systems, already downloaded copies of Deltarune Chapter 1 were updated to Deltarune Chapter 1&2, with Save Data being retained.

Nintendo Switch 2 and PlayStation 5

On April 2, 2025, in a Nintendo Direct presentation, it was announced that Deltarune Chapters 1-4 would be released on the Nintendo Switch 2's launch day, June 5, 2025. Afterwards, it was announced that Chapters 1-4 would be released on PC and Mac (via Steam), Nintendo Switch, Nintendo Switch 2, PlayStation 4, and PlayStation 5.

Development history

Main article: Development history § Chapter 1

Gallery

• 
  Chapter 1's intro animation when completion data is detected
• 
  Chapter 1 promotional art of Susie, Kris, and Ralsei in front of a Dark Fountain

Trivia

• The first installment of the in-universe book series Lord of the Hammer is summarized by the Hammer of Justice as "Chapter 1 The March of the Dark King. The heroes defeat the king and stop the dragon." This parallels the events of Chapter 1; the party defeats King and stops Susie from FIGHTing by befriending her.
• The events of Chapter 1 likely take place on a Thursday, judging by dialogue from the Forgotten Man and the fact that it is the day before the last school day.