If you’re wondering how to keep your weapons, trinkets, slabs, and slab upgrades across playthroughs, you’ll need to know how Infusion works and, because it’s directly related, what Residuum is. 

How to Unlock Infusion in Deathloop

There are two words you need to know if you want to keep yours slabs and weapons, Infusion and Residuum. In Deathloop infusion is a unique ability that Colt can acquire that is used to permanently unlock weapons and items.  Residuum is the glowing, etheral energy you need to collect to power this process.

Early in the game, you’ll get the Arsenal Lead called Ubiquity. This tasks you with venturing into The Complex during the afternoon, with your sights on Wenjie, one of the powerful Visionaries that serve as the collective bosses of Deathloop.

Killing Wenjie isn’t as straightforward a task as it sounds. She split herself into a number of different Wenjies. You will need to take out every one of them, spread across her laboratories. Follow the waypoint to find them, and snuff them all out.  

Once you kill the final Wenjie (killing her for real in this loop), you need to collect the Portable Harvester, located in the small red building closeby. Take that to wherever you killed your last Wenjie, and use it to capture the Residuum she left behind.

Go back to the largest laboratory building. On the bottom floor is the Residuum Intake Socket. Place the filled Portable Harvest inside, and stand in the lit tube. Turn around and shoot the power button on the infuser. Congratulations! You’ve exploded. The bad news is, you are dead. The good news is, you have gained the power of infusion. Not a bad trade, if you ask me.

How to Infuse Weapons and Gear: Residuum

Ok, so you can infuse, but how do you infuse? You start by collecting more Residuum. This can be found scattered around the world in everyday objects that emit a distinctive glow. Walk up to them, and harvest the energy.

The other way to gather Residuum is through defeating Visionaries, including your arch-nemesis, Julianna. Any defeated Visionary leaves a large pool of Residuum to collect.  

It’s also worth noting that you drop any Residuum you’re carrying when you die. You must return to your corpse to pick it up. Don’t forget and leave a large chunk of the stuff behind.

Residuum can only be spent at the loadout screen between missions. Select the Infuse Gear option, choose a category from the menu on the left side, and place your cursor on any piece of equipment.

Weapons and objects will list two numbers. The first is the cost, or the amount of Residuum required to permanently unlock them through infusion. The second number is the sacrifice value. Equipment can be destroyed, and doing so will harvest a certain amount of Residuum. This is great when you are close to unlocking an item, but are just a little short.

Items that have not been infused will display a small hourglass icon, and they will be discarded at the very end of the loop when you start a new day.

Items that are infused will be returned to you at the start of each loop. That means you do have the ability to sacrifice something that has been infused, losing it for the rest of this day, and have it available once you start the next loop.

Mastering infusion is your key to becoming stronger with every cycle through Deathloop. Kill some Wenjies (and yourself), collect Residuum, and start picking and choosing the gear you want in your inventory at the start of each cycle.

That’s all you really need to know about getting started with the Infusion process in Deathloop, as well as how to get Residuum. For more guides to help you break the loop, be sure to keep checking our Deathloop hub.