How to Easily Beat Atomic Boo in Paper Mario: The Thousand-Year Door

Paper Mario: The Thousand-Year Door is a game full of challenges and secrets. One secret challenge is beating Atomic Boo, a hidden boss. Players can find him as soon as they reach Twilight Town in Chapter 4, with the chance to earn great items and gear along the way.

Where to Find Atomic Boo in Paper Mario: TTYD

In Paper Mario: The Thousand-Year Door, players can locate Atomic Boo deep within the Creepy Steeple. He's available as early as players' first visit to the area, even before encountering Chapter Four's main boss.

Upon entering the spooky church, players should head to the back of the main hall to find a star-shaped statue and some skid marks on the ground. Mario can push this statue aside to reveal hidden catacombs underneath. While this path becomes important later in the story, it is accessible from the beginning.

Following the underground path to the left, players will find a secluded room with a single purple box, where they can begin the process of summoning Atomic Boo.

How to Fight Atomic Boo in Paper Mario: TTYD

To summon Atomic Boo, players need to open the small purple box, releasing a torrent of Boos that startle Mario and fly into the rest of the church. One Boo will then ask Mario a pop quiz question: "How many Boos escaped from the box?" The correct answer is 200. Answering correctly rewards Mario with an Ultra Mushroom.

Back in the main hall, a single Boo will ask Mario if he plans to be mean to them. If Mario says no, a flood of Boos will fill the hall. To summon Atomic Boo, Mario needs to use his Super Hammer's Spin Attack to scatter these Boos. Players should let the Boos gather around Mario until text bubbles appear, then use the Spin Attack to knock them away. This needs to be done twice.

Atomic Boo will form and attack Mario, boasting 40 HP, an attack power of 4, and several status effects that can stun, confuse, or make Mario invisible. Players need to time their Action Commands well to avoid these effects and use stylish moves to gain an advantage.

Defeating Atomic Boo rewards Mario with a 50-coin bonus and a decent amount of Star Points. The Boos will scatter, dropping the Lucky Start badge, one of the rarest in the game. Returning to the main hall of Creepy Steeple afterward will make Boos appear as normal enemies.