Artifacts are the last type of gear that you get access to in Borderlands 3.
Every Artifact has some sort of helpful attribute to offer. They can augment parts of your vault hunter’s abilities and even add unique effects to them. Other Artifacts have more universal benefits like making your character invulnerable for a brief time if they drop below 50% health.
Unfortunately, you won’t be able to equip these until you reach a certain point in the story.
To unlock the ability to use Artifacts, all you’ll need to do is progress through Borderlands 3’s story. Eventually you’ll reach a planet called Eden-6. Once you reach the end of that planet’s story missions, you’ll face off against a giant monster protecting the planet’s vault. After you defeat it, you can enter the vault and collect the Eridian Synchronizer which will grant you the ability to equip Artifacts.
Once you’ve unlocked the ability to use Artifacts, you can pick them up like any other loot. It doesn’t appear that you can buy them anywhere, so your only source will be random drops from enemies you kill. While there are a huge variety of Artifacts in the game, you’ll want to make sure that the one you have equipped at any given time is actually useful for your character and the action skill you’re using.