Eridium is Borderlands 3’s rarest currency, but it’s never quite clear where you can spend it or what you can buy.
There are two things you can buy with Eridium: cosmetic items or weapons. The places you can do that are all related to Crazy Earl, the Eridium-obsessed merchant who lives behind a door inside Sanctuary. While these two may be the only way that the game lets you spend Eridium early on, it’s worth knowing that near the end of the campaign you’ll get another option for what to do with your hard-earned Eridium.
To help give you a good idea of what to do with your Eridium, we’ve put together a list of all the places you can spend it, including the endgame option. (But don’t worry, there’s a spoiler warning before you get there.)
Buy cosmetics from Crazy Earl
Crazy Earl sells a variety of cosmetics that can range anywhere from skins, to special heads for your vault hunter, to decorations for your room aboard Sanctuary. Each of these cosmetic items gives something in Borderlands 3 a fresh new look, and each one costs Eridium.
Technically, this is the most valuable thing you can buy with Eridium in Borderlands 3 because it’s the only thing you won’t ever replace — unlike weapons.
Buy extra-strong items from Crazy Earl’s vending machine
This vending machine is always a bit of a mystery. It sometimes has a terrible downgrade to your current loadout, and other times it’s a massive upgrade that will make you feel like a superhero for the next several levels. For that reason, it’s always worth checking out.
The machine itself is in front of Crazy Earl’s door and its deal of the day is often where you’ll find the best items. The one word of warning we can give for this vending machine is to read everything about the weapon you’re buying first. Sometimes these guns can get a little weird and might not be exactly what you wanted.
Create guns with the gun-creator gun
Yep you read that right. This “weapon” is one of the last things you get in Borderlands 3. It’s a gun that makes guns. The gun uses small amounts of Eridium as ammo, and in return it shoots out a fountain of weapons.
We haven’t quite spent enough time making weapons with it to say what the best rewards it can give are, but in our experience it’s mostly greens and blues when you’re around level 40. Some of those weapons were significantly better than the ones we have, so it may be a legitimate way of getting gear in the late-game.
Most importantly though, it’s far and away the most fun way to spend Eridium. Each shot feels like hitting the jackpot on a slot machine, even if you don’t end up with an upgrade once you’ve sifted through your winnings.