Undertale Yellow Decibat Fight

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Undertale Yellow Decibat Fight Challenge | Learning Justice in the Dark Ruins

Released:October 21, 2025

Alternate universe Undertale

🎮 Controls: Arrow keys to move, Z to select, X to unselect.

👨‍💻 Created by dino7597 on Scratch.

Decibat, the bat-like Mini-Boss from the Dark Ruins

The Decibat Fight serves as the first Mini-Boss Clover encounters in the Dark Ruins in Undertale Yellow. This encounter is cleverly designed to test the player's understanding of the core Undertale mechanic: ACT (Action) vs. MERCY (Forgiveness). It sets a gentle tone for Clover's journey of 'Justice' in Undertale Yellow, challenging players to find a way to soothe a frightened soul rather than simply defeating it.

Decibat Battle Guide: The High-Decibel Challenge

Decibat's fight in Undertale Yellow is all about emotional engagement, requiring players to lower the monster's aggression through non-lethal means to achieve a Pacifist resolution. Decibat is a common bat-like monster whose name, a pun on 'Decibel,' reflects his sound-based attacks. He is inherently timid and uses loud, high-pitched screeches to scare off intruders, primarily out of self-preservation.

Attack Pattern: The High-Decibel Barrage

Decibat's attacks in Undertale Yellow are exclusively sound- and sonic-wave-themed, presented as sharp, geometric bullet patterns. This fight serves as the crucial introduction to the Blue/Orange mechanics central to Undertale Yellow combat:

•Blue/Orange Waves: Decibat alternates between basic Blue waves (requiring the player to STOP MOVING) and Orange waves (requiring the player to KEEP MOVING). This core mechanic is essential for mastering Undertale Yellow's combat system.
•Wave Multi & Mini: Advanced waves include large multi-colored attacks and small waves that change color every time they bounce off a wall, demanding precise timing and anticipation.
•Stalagmite: Sound-based stalagmites appear in a set sequence at the top of the board, then fall in the same order.
•Resonance Damage: If Clover fails to interact via ACT for too long, Decibat will unleash a powerful, area-wide resonance sound as a penalty, forcing players to be proactive.

Winning Strategy: ACT and Soothing

The Pacifist route victory hinges entirely on interacting with Decibat's fear, not engaging in combat:

•'Clog Ears' / 'Block': Using this ACT option allows Clover to momentarily block out Decibat's noise, calming the monster and giving the player a reprieve. This strategy is crucial for Undertale Yellow's Pacifist route.
•MERCY Victory: Repeatedly using the 'Clog Ears' ACT until Decibat is sufficiently tired will turn the MERCY option yellow, allowing Clover to spare the anxious creature.

Decibat Fight gameplay screenshot showing the sonic wave attacks

Comments

Silence the Screeches. Claim the MERCY.

Begin the Battle!

Undertale Yellow Decibat Fight

Undertale Yellow Decibat Fight Challenge | Learning Justice in the Dark Ruins

Game Overview

Decibat Battle Guide: The High-Decibel Challenge

Silence the Screeches. Claim the MERCY.