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Luigi's Mansion 3: Rooftop: final boss walkthrough

The last fight on the hotel roof.

  • About 12–21 min in the videos
  • 1 part · 4 steps
  • 1 boss

Compiled from 2 playthrough videos and 6 guides · checked Oct 18, 2026

0 of 1 done
Video: ProsafiaGaming on YouTube. Loads from youtube-nocookie.com only when you press play.

What each player can do here

P1 · Luigi
  • Luigi holds the Poltergust G-00 and the flashlight: stun ghosts with the Strobulb, then vacuum and slam them. The run only ends if Luigi runs out of health.
P2 · Gooigi
  • Gooigi walks over spikes and slips through bars and tight spaces that stop Luigi. Water and fire empty his health at once and send him back to Luigi.
  • Gooigi grabs the boss's tongue together with Luigi for the slams.

If your skill levels differ: Losing health is never game over for Gooigi; the run only ends when Luigi runs out. So the newer player usually takes Gooigi and the steadier player takes Luigi. How to split the roles

The roof

Part 1 of 1. Win the final fight.

  1. BothWhen the roof tiles glow purple, move to a tile that is not lit. Sidestep the tongue slams and walk under the spinning tongue.
  2. BothHe throws a spiked ball that breaks into bombs: leave the one about to blow, vacuum another and fire it into his open mouth.
  3. BothWhile he is down, both of you grab his tongue with the vacuum and slam him.
  4. BothHe then splits into a copy, and later into three; only the real one can be hurt, so keep track of it and repeat the bomb and slam.

Where people tend to fall

  • The red bombs are the ones about to explode.

Boss

King BooThe final boss

  1. One: Dodge the lit tiles, tongue and fireballs; bomb into the mouth; slam together.
  2. Two: He adds a copy and a slam with a shock wave; hit the real one.
  3. Three: Three of him and heavier bomb rain; bomb the real one and slam.
Sources (8)

Steps compiled from 2 playthrough videos and 6 text guides, checked Oct 18, 2026, and written in our own words. We did not play the game for this guide.