I understand the basics. Start a campaign on D&D Beyond, invite players when you have a Master subscription, and click "enable content sharing". But what are the limits to the shared content? I have all but 2 sourcebooks purchased on here. I have a buddy who is also a DM, who is trying to experiment with things. So I'm wondering what the exact reach is of the shared content? Like can he go into Creations and create random characters that are not assigned to my campaign, using the shared content? Can he access any of the Sourcebooks freely, like the books themselves, not the content in them. Can he open and read them freely on D&D Beyond? Can he access all shared content outside of the campaign as long as he is indeed, inside of the campaign with content sharing enabled?

So. You yourself do not have to be the one to create the campaign, nor be the one with the master tier sub.

Anyone can create the campaign, if you join a campaign and someone enables Content Sharing (could literally be anyone, not even the DM). ALL content owned by ALL players will be able to be used/viewed. 

Yes, you/your friend would be able to go to sources, click a book and read through it (so long as content sharing is enabled and you share at least one content shared campaign with them). But you'd only be able to make characters with that shared content in that campaign (you could then leave that campaign, but not be able to add items etc that the person doesn't already own themselves). You can also make characters, and unassign them for others to claim in the campaign as well. 

Quote from Inumiru >>

So. You yourself do not have to be the one to create the campaign, nor be the one with the master tier sub.

Anyone can create the campaign, if you join a campaign and someone enables Content Sharing (could literally be anyone, not even the DM). ALL content owned by ALL players will be able to be used/viewed. 

Yes, you/your friend would be able to go to sources, click a book and read through it (so long as content sharing is enabled and you share at least one content shared campaign with them). But you'd only be able to make characters with that shared content in that campaign (you could then leave that campaign, but not be able to add items etc that the person doesn't already own themselves). You can also make characters, and unassign them for others to claim in the campaign as well. 

 Thank you so much, this cleared it up!

For the limits:

Campaigns with Content Sharing: 5

Players per campaign with Content Sharing: 12 (including DM)

Characters per campaign with Content Sharing: 99.

If your player with the master subscription has already used their allotment of 5 content shares, then someone else will need to get a master tier subscription. It doesn't have to be the DM that does this.

Is there a way for the DM to have NPC character sheets in the campaign but not viewable by the players with content sharing turned on? I'd like to use content sharing for most of the character sheets but be able to keep a few secret character sheets that I can make visible when it's time to reveal them.

Good to know. Tysm.