Wondering what those mysterious glowing items in Deathloop are for? Or perhaps you’ve heard of residuum, but aren’t sure how to use it? On the island of Blackreef, time doesn’t progress normally – at the end of each day, the cycle begins anew, resetting everything to the way it was at the start of the day. Well, mostly everything.
As you begin to play Deathloop, you may notice glowing objects, but have no way of interacting with them or finding out what they do. After completing a certain mission in the story, you’ll be able to obtain residuum by interacting with these objects. So what exactly does residuum do?
Every time you get sent back to the beginning of the loop, you lose all the equipment you picked up on your previous attempt. However, if you infuse them with residuum, you can carry weapons and powers forward with you, even after you run out of Reprise uses and get sent back to the start of the day. Essentially, it allows you to gradually accumulate resources, kitting you out for subsequent attempts. If you wish to figure out more about residuum, be aware that there are mild spoilers ahead.