The Pacifist Route is one of the three primary routes in Undertale Yellow . Like in Undertale , it is the ending achieved by not killing any monsters or robots . Depending on whether Clover spares or kills the final boss , it ends with the True Pacifist or Flawed Pacifist Ending.
The Pacifist Route is attained by simply completing the game without killing a single monster or robot. Unlike Undertale , completing a Neutral Route is not a prerequisite for completing a Pacifist Route.
The choice on whether or not to spare the final boss of this route determines which variant of the Pacifist Ending is obtained.
After sparing an area's boss, all enemies in that respective area become NPCs throughout the area for Clover to talk to when they backtrack. This is exclusive to the Pacifist Route.
When Clover is ready to leave, Dalv tells them that he plans to go to Snowdin after he packs up and leaves the Dark Ruins, which he says will take a few days.
Snowdin in the Pacifist Route is identical to a Neutral Route in which no monsters were killed in the area. [ note 1 ]
During Ceroba 's introduction at the Wild East , she is more friendly to Clover than she is on a Neutral Route and expresses that she wants to help them leave the Wild East.
After reaching the Sunnyside Farm and gaining access to Fast Travel , Clover can receive a letter from Dalv telling them that he moved to Snowdin. If Clover travels back to Snowdin at this point, they can find Dalv and other Dark Ruins monsters throughout Snowdin.
Ceroba goes with Clover through the Steamworks , wanting them to travel with her to the Lab to find Kanako . This results in a different path than in other routes.
As Ceroba prepares to lead Clover to the Lab, they are stopped by Starlo and Ed, who discovered a trapdoor leading to a bunker full of incriminating research while preparing a party for Kanako's return. When Starlo demands to know what Ceroba is planning, she flees through the elevator, with Starlo chasing after her. Before leaving, Starlo orders Ed to take Clover back to the Wild East.
Once back, the others Feisty Four members show up. Martlet arrives as well, as she was contacted by Moray. Martlet convinces Ed to have Clover follow her to the Estate to investigate while he explains what he knows to the group.
At the Estate, they locate the trapdoor Ed discovered. They enter Chujin's secret study and watch his video journal. These videotapes detail his plans to create a serum allowing any monster to become as strong as a Boss Monster, which led to him experimenting on himself and causing his demise. His last tape is him telling Ceroba to find a human with a pure SOUL and kill them to finish his work. Horrified, Martlet takes Clover out of the Estate and meets up with the Feisty Four, convincing them that she and Clover need to go and stop Ceroba. She flies ahead to Hotland and the Feisty Four wish Clover luck. Clover begins to walk away but is stopped by Flowey, who mocks them for trusting Ceroba. However, rather than continuing to tell them to leave Ceroba, Flowey says that he supports Clover and is curious about what will happen next.
At UG Apartments , Clover meets up with Martlet on its roof. She explains where Ceroba and Starlo are. She tells Clover that they are a kind and peaceful person in spite of all their hardships, contrasting what she was told as a Royal Guard. She then promises Clover that after they diffuse the conflict with Ceroba, she will convince Asgore to let Clover free and promises to meet them again when the barrier one day breaks. The two head to New Home .
Once there, they find Starlo and Ceroba in a standoff, where Ceroba reveals that she believes Kanako is dead. Despite both Martlet and Starlo's attempts, Ceroba refuses to back down. Martlet attempts to flee with Clover, but Ceroba knocks out both her and Starlo with little effort. She goes on to state that Clover, while admirable, is naïve for thinking that the five humans can be saved or that Asgore would let Clover go. Admitting to be a hypocrite and no better than Asgore on morality, she reasserts she will protect Monsterkind by completing Chujin's work.
She and Clover then fight. At first, Clover survives Ceroba's attacks, but once brought to the tipping point, she assaults them with a barrage of attacks. Before the last hit can strike, Clover unlocks the Yellow SOUL mode and blasts back. Realizing the situation, she puts on Kanako's mask and takes a kitsune-like form. Clover eventually cracks the mask, which causes a memory to play out before the two of them. The memory is of Chujin on his deathbed, who tells Ceroba of the bunker where he worked on his project, with Kanako having heard everything. Ceroba is initially startled by Clover being in her head, but continues fighting. Clover manages to chip away more of the mask, revealing another memory of Kanako and Ceroba in Chujin's bunker. In this memory, Kanako finds out about Ceroba's plan to create a Boss Monster serum. Ceroba's note, which she threw in the garbage, alleges that she removed any corruption Chujin's previously used serum held, and so Kanako pleads Ceroba to volunteer as a Boss Monster in the experiment. Ceroba then injects Kanako with the serum, causing her to fall down. As Ceroba lays silently before Clover, she states she knows she is unforgivable but is unable to let go, and gets up one last time.
Eventually, Clover manages to overwhelm and destroy the mask, reverting Ceroba back to her normal state. As she lays defeated before Clover, she realizes her attempts at fulfilling Chujin's legacy costed her family, and made her attack her friends and a child, for a plan that may not even work. Racked with guilt, she begs Clover to finish her. In the final scene of the battle, Clover is only given options to kill or spare Ceroba, where sparing leads to the True Pacifist Ending, and killing leads to the Flawed Pacifist Ending.
Most might act cheerful, but life down here... ...It's hopeless.
Ceroba, in Clover's flashback sequence, before Clover makes the decision to sacrifice their SOUL
The True Pacifist Ending is reached by selecting the Mercy option 3 times at the end of the final battle against Ceroba . Ceroba, confused as to why Clover is sparing her, is interrupted by Starlo waking up and brushes off her concerns as payback for how he acted back in the Wild East. Martlet wakes up as well and tries to help Clover escape before Ceroba calms her down by revealing that Clover already won the fight. Ceroba then apologizes for how she acted, having been too obsessed in her quest to fulfill Chujin's legacy, before being comforted by Starlo. Martlet also promises to use her Royal Guard connections to the royal scientist to locate Kanako. Ceroba apologizes to Clover for attacking them, stating that spending time with them helped her forget her troubles. Clover cuts her off by walking up and hugging her.
With any obstacles now clear, Martlet prepares to take Clover to Asgore and the barrier, but Ceroba shoots it down, stating that Asgore would take their SOUL. Martlet, Starlo, and Ceroba all argue as Clover thinks to themselves. Remembering that monsters have suffered while trapped in the mountain, Clover ultimately decides to offer up their own SOUL so that one day, monsters can be free. Despite Martlet and Starlo's attempt to convince them otherwise, Ceroba accepts their choice and agrees to take their SOUL. The four then share one final hug before Martlet and Starlo leave, with Clover giving them their hat and gun respectively as a farewell present. Ceroba takes their SOUL and Clover sends her off before collapsing. Flowey is then heard, expressing his disappointment at Clover becoming "predictable" by sacrificing themselves before stating that while he could RESET everything, he believes that Clover has earned their rest. He holds out hope that a future human would give him what he wants. Flowey then says his farewells to Clover before leaving, stating that they'll meet again (likely a reference to Flowey's plans to take the human souls). Clover then crawls up the side of the wall to pass away peacefully.
As the credits roll, the fates of many characters, both major and minor, are shown playing out. It shows:
In Waterfall , Martlet is seen preparing a small raft to send Clover off properly, before placing Clover's hat in the raft. As she does so, she reveals she declined a promotion and quit the Royal Guard for more important matters. Ceroba and Starlo arrive. Starlo puts Clover's gun in the raft and Ceroba then reveals that she invited Dalv to join the event. Starlo adds the Safety Glasses on the raft as well before Martlet places the raft in the water and sets it off, everyone saying their farewells to Clover. The Special Thanks credits play to the boat sailing down the river. After the last set of credits roll, the raft falls into the Garbage Dump, with the hat and gun landing on a patch of golden flowers.
The game briefly shows Frisk calling for help during the Omega Flowey battle and Clover's SOUL answering it. The game then ends on a cinematic shot of Clover's hat and gun before closing.
Opening the game again has Flowey conflicted on whether or not he should try again to get a different ending, or just accept it and wait for another human to fall. Then, the player is given the choice to RESET or wait.
Regrettably.. The one thing these encounters never are is "different." Not in the end.
The Flawed Pacifist Ending (also known as the Asgore ending [ 2 ] ) is reached by selecting the Fight option at the end of the final battle against Ceroba. She thanks Clover for freeing her of her guilt, happy to be reunited with Chujin again. Upon doing this, Clover kills Ceroba, leaving behind Kanako's shattered mask. Once Starlo and Martlet awaken to witness the scene, Starlo becomes furious and lashes out at Clover for killing his best friend, while Martlet defends them, stating that Clover's actions were justified since Ceroba was unreasonable and violent. Starlo disregards the idea of justice and, carrying Kanako's shattered mask, silently leaves New Home.
Martlet guides Clover to Asgore 's throne room, presenting Clover to him, which momentarily shocks the king. Martlet attempts to reason with Asgore, but he is undeterred and reaffirms his no-tolerance policy towards humans, saying that Clover is not any different from the others. Martlet is devastated by the turn of events and asks Clover to defend their case, but Clover accepts the fate that stands before them and quietly indicates that Martlet should be on her way.
After Martlet leaves in sadness, Asgore brings Clover to the Barrier and reveals his five collected human SOULs. Clover briefly looks at them and then draws their revolver. Briefly, Asgore gives his sympathies to the child, saying he is well aware of the feelings they are experiencing. He promises he will make the fight quick before initiating a battle.
This battle is different from the standard encounter format of Undertale and Undertale Yellow : while there is a Bullet Board and a yellow SOUL that the player can control, no other parts of the user interface are present, including Asgore's battle sprite. Attacks from Asgore keep coming in one never-ending wave, most being similar to the ones found in Undertale , but also including some that cannot be dodged. The player never gets their turn and Asgore's turn continues until Clover is killed, at which point one of the empty SOUL receptacles appears and envelops Clover's SOUL. The receptacle joins the five others, and Asgore apologizes to the human one last time before the credits roll.
Post credits, Flowey is seen talking to himself, and decides not to RESET things, instead opting to wait for the next human to fall so that his plans can come to fruition.