To get the True Pacifist ending in Undertale, follow these key steps:
- Complete a Neutral Route first. The True Pacifist ending is only available after finishing a Neutral run
- Do not kill any monsters. You must kill absolutely no one throughout the game. Killing even one monster locks you out of the True Pacifist ending
- Spare every monster you encounter. Use non-violent actions to resolve battles, such as complimenting or fleeing. Bosses must also be spared
- Befriend Papyrus. During your encounter with Papyrus, dodge his attacks and spare him repeatedly until the fight ends peacefully. Afterwards, accept his invitation to go on a date at his home in Snowdin
- Befriend Undyne. When fighting Undyne, flee when she attacks and then find her resting on the bridge to give her water. Later, visit her house and follow the events there to solidify your friendship
- Go on a date with Alphys. After defeating Mettaton peacefully, return to Alphys’s lab and give her a letter from Undyne. Complete the date with Alphys, then enter the True Lab through the bathroom to explore it fully
- Backtrack after the Neutral ending. After defeating Asgore in the Neutral run, backtrack out of The Core so your phone works. Undyne will call you to deliver a letter, which starts the True Pacifist quest
- Do not fight during the final battle with Asriel. Instead, dodge attacks and use the "Dream" and "Hope" actions to heal and defend. Focus on saving the souls of your friends by bringing back their memories until the battle ends peacefully
Following these steps ensures you achieve the True Pacifist ending, which features a heartfelt resolution and credits sequence with all the monsters you befriended
. Summary:
- No kills
- Spare all monsters and bosses
- Befriend Papyrus, Undyne, and Alphys (go on their dates)
- Complete the True Lab exploration
- Finish with the non-violent final battle against Asriel
This route provides the most fulfilling and "true" ending to Undertale
