Sharing a class with an access code, and what forking actually protects

Sharing a deck raises an obvious question the moment more than one person can touch it: what happens when someone edits a card they didn't write? Encodr's answer is that they can't - not directly - and the way around that is what makes shared decks safe to hand out in the first place.

Sharing itself

A class - or any deck - can be shared with one access code. Anyone with the code enrolls without needing an account-by-account invite, which is the same mechanism curated classes use to ship pre-built content: enroll, and it appears on your Home and in your Feed alongside everything else you study.

What happens when you edit someone else's card

Try to change a card on a deck you don't own, and Encodr doesn't edit the shared original - it creates your own personal copy of that card first, a fork, and edits that instead. The person who shared the deck never sees your change, and your copy of the deck moves forward independently of theirs from that point on. It's the same principle as forking a repository: you get your own line to edit freely, and the shared original stays exactly as its owner left it for everyone else still using it.

Why this is the part that makes sharing work at all

Without forking, sharing a deck would mean either locking it read-only for everyone but the owner, or letting one person's typo fix silently rewrite what an entire class studies. Neither is workable. Forking lets you fix a card that's wrong for you, add your own mnemonic, or reorganize your copy, without any of that leaking back into the version the next person enrolls into. Curated classes take the read-only side of this further still - since no single enrolled student owns them, editing is disabled entirely, and the fork-on-edit behavior only applies to decks a real person shared.