Deltarune
Deltarune is an episodic role-playing video game by American indie developer Toby Fox. Set in a parallel universe to his 2015 game, Undertale, the game follows Kris, a human teenager predetermined to save the world alongside Susie, a monster, and Ralsei, a prince from the Dark World. Throughout the story, the party establishes relationships with a variety of allies and opponents.
The game's combat system is turn-based and uses bullet hell mechanics. Like in Undertale, enemy encounters can be resolved peacefully or through violence. The game shares several characters and gameplay elements with Undertale, but takes place in a separate setting and features an overhauled battle system with multiple party members.
Development for Deltarune began in 2012. Its first two chapters were released as free demos in 2018 and 2021 respectively, while the third and fourth chapters were made available in 2025 with its paid release. Subsequent chapters are planned as free updates. Initially released for macOS and Windows, it was later ported to the Nintendo Switch and PlayStation 4 in 2019, followed by the Nintendo Switch 2 and PlayStation 5 in 2025. The game has been praised by critics for its soundtrack, characters, narrative, and sense of humor.
Gameplay
Deltarune is a role-playing video game with a top-down perspective. The player controls a human named Kris Dreemurr and has a party of other characters who they select actions for during battle. The game features both overworld and combat sections. In the overworld, the player can solve puzzles, collect items, and interact with characters and the environment. Unlike Undertale, Deltarune does not have a random encounter system. Instead, players can see the enemies in the environment before they encounter them, allowing for the possibility of avoiding or deliberately initiating combat.The game uses a turn-based combat system, where players can choose from a set of actions each turn: fight, act, item, spare, and defend. As in Undertale, players control a heart-shaped soul in a fixed area and must dodge enemy attacks in the form of bullets, though the exact mechanics are sometimes unique to the respective enemy. Defending or "grazing" an incoming attack by letting it come close to the heart without getting hit by it increases the tension points gauge, which allows party members to use spells or particular acts. For example, Ralsei can pacify tired enemies with a spell.
Using acts and spells allows players to spare enemies non-violently; from the second chapter, this can allow them to be recruited to live in the player's Castle Town. Alternatively, fighting an enemy, which also increases TP, can lead to them being defeated violently and causes party members to gain HP after the battle is concluded.
Plot
Deltarunes narrative spans multiple chapters, of which four have been released, with three more being planned for a later release. Although it features characters and elements from Undertale, it takes place in a parallel universe distinct from that game's setting.Chapter 1 – The Beginning
The game begins with a voice prompting the player to create an avatar, but the "vessel" is ultimately discarded, as "no one can choose who they are in this world". Instead, the player is given control of human teenager Kris, who arrives to school late. After being paired up with their delinquent monster classmate Susie for a group project, their teacher, Alphys, sends the two to get supplies. However, the supply closet shuts behind them and they fall into a strange realm—the Dark World—where they meet the dark prince Ralsei. He tells them of a prophecy stating that the three of them are heroes destined to close the geyser-like Dark Fountains that give form to the Dark Worlds. A new Dark Fountain has created a Dark World next to Ralsei's, ruled by the tyrannical King. Susie, uninterested in Ralsei's prophecy, joins King's son Lancer in fighting Kris and Ralsei, but both are convinced to change sides and join the party.Lancer refuses to confront his father or to see his new friends hurt, so he imprisons them in King's dungeon. Susie frees Kris and Ralsei and fights Lancer, but reconciles with him and promises not to hurt King. The three confront and defeat King, who remains unrepentant. After sealing the Dark Fountain, Kris and Susie wake in an unused classroom. The room is filled with objects resembling characters, suggesting that Dark Worlds are reflections of ordinary rooms, and their inhabitants, known as Darkners, are simply objects within those rooms. That night, after returning home, Kris rips out their soul, locks it away, and draws a knife.
Chapter 2 – A Cyber's World
After school the following day, Kris and Susie return to the closet Dark World and reunite with Ralsei. He instructs them to bring the items from the unused classroom into the closet, restoring them to their Darkner forms. He then tells them to focus on their school project with classmates Noelle and Berdly. Arriving at the library's computer lab, they discover a newly created Dark World ruled by a computer named Queen. Queen recruits Berdly to her side and attempts to recruit Noelle. The group finds Ralsei, but they soon split up. Kris joins Noelle in helping her evade Queen's attempts to recruit her.Queen captures everyone, but Kris and Susie escape and convince Berdly to switch sides before later reuniting with Ralsei. Queen reveals that the Dark Fountain was created by an entity known as the Roaring Knight, and that she intends to force Noelle to open a Fountain, which any inhabitant of the Light World can do. She threatens Noelle and the party with a giant mech, but they manage to make her realize the error of her ways. Berdly then attempts to create a Fountain, but Ralsei warns him that opening too many Fountains will cause an apocalyptic "Roaring".
Kris closes the Fountain, and the four awaken in the computer lab; Noelle and Berdly dismiss the events as merely a dream. Kris heads home, and their mother, Toriel, invites Susie to spend the night. While Susie and Toriel are occupied, Kris secretly rips out their soul, locks it in the bathroom, and briefly leaves the house off-screen. Toriel finds her car tires slashed, prompting her to call the police. After everyone else falls asleep, Kris rips out their soul once more and creates a Dark Fountain in the living room by stabbing the floor with their knife.
Chapter 3 – Late Night
Kris and Susie awaken in the Dark World Kris created. After reuniting with Ralsei, they meet Tenna—a Darkner created from Toriel's television—who convinces the trio to star in various game show segments. Sneaking away from Tenna, the party discovers Toriel being held hostage by Tenna inside of a giant toy capsule.The party demands Tenna stop the games, allowing them to seal the fountain and return home with Toriel, but he refuses; feeling abandoned and obsolete, he explains that the Roaring Knight promised him relevance in exchange for keeping the Fountain open. After the party defeats Tenna, Ralsei and Susie comfort him, explaining that he has already spent years bringing joy and can find love and appreciation in another household.
However, he is suddenly attacked by the Knight, who also attempts to capture Toriel. The party then fights the Knight and is ultimately defeated, only to be rescued by the arrival of police officer Undyne, who the Knight kidnaps. Kris and Susie chase the Knight through the Light World until reaching a locked bunker which appears to have a Dark Fountain inside of it. The door shuts before they can enter, but they discover a lock requiring three numeric codes. Susie runs back to Kris's home to rescue Toriel. The chapter ends with the bunker door opening in front of Kris.
Chapter 4 – Prophecy
After Kris and Susie close the living room Dark Fountain, Toriel wakes Kris and Kris and Susie go to church. After questioning townsfolk about the bunker, the two conclude that their best lead on the codes is Noelle's mother, Mayor Carol Holiday. They visit the Holidays' house, where Susie distracts Noelle while Kris searches. In the bedroom of Noelle's missing sister Dess, Kris finds a code in a guitar, but Kris rips out their soul before it can be fully read. The player-controlled soul enters the house's ventilation, finding Kris on the phone with an unknown person who discusses the Knight's actions and instructs them to prevent Susie from getting the guitar. Kris fails to prevent Susie finding the guitar and returns the soul to their body, but Carol returns home and expels Susie from the house before she can memorize the code.Upon returning to the church, Kris and Susie find it transformed into a Dark World containing depictions of the prophecy. In the Dark World, they reunite with Ralsei and encounter an old man formed from the ashes of dead Light World inhabitant Gerson Boom. Ralsei admits that he has been hiding parts of the prophecy from Kris and Susie because he believes the truth would be too upsetting.
The party encounters the Knight, who opens a Fountain within the Dark World, creating a "Titan", a harbinger of the Roaring. The party defeats the Titan with help from Gerson. Against Ralsei's protests, Susie runs ahead and sees the ending of the prophecy. She smashes it before the player sees, dismissing it as something the party would never let happen. After sealing the Fountain, they return home to find Toriel drunk with the grocery store janitor, Sans. Susie leaves and Kris, alone in their bedroom, receives a phone call from an unknown source. During the call, a promise between the caller and Kris, previously made off-screen without knowledge of the player, is referenced.
Alternate route
During Chapter 2, the player can initiate an alternate route by backtracking and forcing Noelle to freeze every enemy encountered. Spamton, a spambot normally encountered in an optional sidequest that leads to his secret boss fight, sells the powerful Thorn Ring to Noelle, which she can then equip. Subsequently, during the battle with Berdly, the player orders Noelle to use her new spell, Snowgrave. After initially resisting, she freezes Berdly whole, becoming shaken by her own actions and too exhausted to participate in Queen's plans. Ralsei informs Queen of the Roaring preemptively, which prevents her battle. With the Darkners' absence, Spamton is able to take over Queen's mansion and attempts to stop Kris before being frozen by Noelle as they seal the Fountain. In the Light World, Berdly is found in a coma, leading Noelle to question if the events in the Dark World really were a dream. Chapter 2 ends identically to that of the normal route, with Kris opening a Dark Fountain.Chapter 3 proceeds as normal, but in Chapter 4, Noelle asks Kris if they can talk privately after Kris removes the soul. Entering the ventilation system, the soul overhears a conversation between Kris and Noelle, where it is revealed that Kris took Berdly to the hospital the previous night before visiting Noelle. During their visit, Kris claimed the Dark World was just a dream and removed a thorn—the Thorn Ring's form in the Light World—from her hand. The soul then enters the room, takes control of Kris, and directly communicates with Noelle, revealing to her that the soul can read her thoughts and that the previous events actually happened, before forcing the thorn back into her. Afterwards, Kris furiously throws the soul in a trash can and beats it up before Carol orders everyone to leave the house. The chapter continues mostly unchanged until the end, when Carol leaves a phone message for Kris, telling them that Noelle is looking forward to seeing them at the festival tomorrow.