Information about how to solve the Lamp Puzzle in the Library of Zoltan Kulle in Diablo Immortal. How to light all nine Lamps at once.

To advance the main questline you’re usually tasked with slaying various monsters, but in the Library of Zoltan Kulle you’ll get an odd objective to solve a puzzle by lighting nine Lamps simultaneously. What better way to break up the monotony of combat than by throwing in a very mundane puzzle you’ve probably seen multiple times before?

You’ll find a grid of nine Lamps lined up in a three-by-three formation. Initially none of the Lamps are lit up, but when you interact with a Lamp, it’ll light it up, as well as toggling every linearly adjacent Lamp. If an adjacent Lamp is lit, it’ll be snuffed, and if it’s unlit it’ll be kindled. To light all nine Lamps you’ll need to interact with the Lamps in a specific order: first hit all the corner Lamps and work your way clockwise or counterclockwise until all the corner Lamps are lit. Lighting the Lamps in this sequence will light the corner Lamps and light - then squelch - the adjacent Lamps on the grid perimeter. This should leave the center Lamp unlit as well as the four adjacent Lamps. Simply interact with the middle Lamp to light it and the other four Lamps, solving this puzzle.

Check out the gif below for a video guide, if necessary: