Underswap Papyrus Fight Simulator

How to Play Underswap Papyrus Fight

Underswap Papyrus Fight is a focused fan-made Undertale battle built around US Papyrus. Click inside the game window first so the game can receive your keyboard input, then use the movement and selection keys to work through the encounter.

The original creator, loganvcairns, described this project as a follow-up to his Underswap Sans fight and specifically warned players that the battle is meant to be difficult. This is not a casual Papyrus encounter where you can expect to clear every attack on your first attempt. Learning the timing and movement of each section is part of the challenge.

Use either the Arrow Keys or IJKL to move. Press Z to select options and advance dialogue, and use X to deselect or skip dialogue. If the controls do not respond immediately, click the game area again before pressing the keys.

This page contains the standalone Undertale: Underswap Papyrus fight project. It should not be confused with our regular Papyrus Fight Simulator, Genocide Papyrus Fight Simulator, or Disbelief Papyrus Fight Simulator. Although all of them feature Papyrus, they are separate fan-made battles with different concepts and gameplay.

Controls

What Is Undertale: Underswap Papyrus Fight?

Undertale: Underswap Papyrus fight is a fan-created browser battle originally made by Scratch creator loganvcairns. The creator referred to the character in this project as US Papyrus, short for Underswap Papyrus, and described the game as a follow-up to his earlier US Sans fight.

Rather than trying to recreate an entire Undertale playthrough, the project is centered on one difficult Papyrus encounter. That makes it useful for players who specifically search for an Underswap Papyrus fight and want to jump straight into the battle without progressing through a larger fangame.

The project was created with a fan-made Undertale battle creator credited by loganvcairns to Pococikapusta, while Undertale itself is credited to Toby Fox.

This distinction is important because there are many different Papyrus fangames online. “Underswap Papyrus,” “Genocide Papyrus,” and “Disbelief Papyrus” are not interchangeable names for the same battle. The version hosted on this page specifically comes from the project titled Undertale: Underswap Papyrus fight.

About the Original Project

The version featured here comes from Scratch project 118377554, titled Undertale: Underswap Papyrus fight, by loganvcairns. The project was originally shared in 2016 and remained part of the creator's collection of Undertale and AU battle projects.

loganvcairns also created several other Undertale fan battles, including Genocide Papyrus and UnderSwap Sans projects. That is one reason these games can easily be confused when collecting and organizing old browser versions.

For this page, however, the identity is clear: this is the creator's standalone Underswap Papyrus project, not his Genocide Papyrus battle.

A Difficult US Papyrus Battle

The original creator openly describes the fight as difficult and compares its intended challenge to Sans. He also notes that he had personally beaten the project many times in response to players saying that it was impossible.

That is a useful expectation to have before starting. Do not judge the game by whether you survive the first attempt. Treat each run as a chance to understand how the next section works.

Try to avoid large panic movements. Small corrections usually give you more control than holding a direction continuously. Once you recognize a section you have already seen, concentrate on repeating the movement that worked previously instead of improvising from scratch.

Because the game uses keyboard controls, it is best played on a computer with a physical keyboard. The original project does not list native touchscreen controls, so do not describe this as a mobile-optimized game.

Performance Note

The original Scratch project includes an important warning from the creator: on older or slower computers, the game may lag, and this can make attacks appear slower or make their spacing feel different from what was intended.

If the battle feels abnormally slow, inputs appear delayed, or the timing seems inconsistent, first make sure no unnecessary browser tabs or heavy applications are running. Reloading the game may also help.

This matters especially in a difficult battle where timing is part of the challenge. Poor performance can make the encounter feel different from the way the creator designed it.

Tips for Underswap Papyrus Fight

• Click the game before using the keyboard. The browser needs to give focus to the embedded game before it can reliably receive your input.
• Pick one movement scheme. Both Arrow Keys and IJKL are supported. Use whichever feels more natural, but switching back and forth during the fight usually makes movement harder.
• Use short movements. When an attack gives you limited room, tapping a direction can be easier to control than holding the key down.
• Learn instead of rushing. The creator intentionally made the fight difficult. Repeated attempts are expected, so use each failure to remember where the dangerous sections occur.
• Use Z and X deliberately. Z handles selection and dialogue progression, while X lets you deselect or skip dialogue.
• Check performance if the timing feels wrong. The original creator specifically warned that lag can affect how the fight feels.