Destiny 2's economy is a bit of a rat's nest of interloping currencies, items, and more, and in 2020 Bungie introduced Exotic Ciphers.
Here's how to get them, and what they do, but remember - you can only hold one at a time.
How To Get Exotic Ciphers
At the time of writing, you can snag Exotic Ciphers in two different ways.
For one, the game's season pass will offer them out as rewards for levelling up, usually at around the halfway mark.
Looking to level up your season pass quickly? We've got you covered.
The other way you can get it is by visiting Xur.
Destiny's travelling exotic merchant can be found with our handy guide, and he alternates between the same three spots:
When you interact with Xur, he'll give you the option to pick up a bounty that awards an Exotic Cipher.
What Do Exotic Ciphers Do
Once you have an Exotic Cipher, you can then turn this in at the Monument to Lost Lights kiosk back at the Tower.
It's located just next to the Vaults, but you can also offer it to Xur for one of his 'random exotics', although collectors beware - these exotics pull from the same pool, so preview the engram first to ensure you don't end up with a duplicate.