Every table has its own ideas: a species that isn't in the book, a spell you dreamt up, a monster for your big finale. Homebrew lets you add them, and they work just like the official ones.
Open Homebrew
On your campaign's Build page, press Homebrew.
There are nine kinds, each with its own tab: species, classes, subclasses, backgrounds, feats, spells, equipment, magic items and monsters.
Homebrew your players have asked you to approve. Open one to read it and answer.
Wren’s Spark
Spell · player of Wren Ashdown · The Demo Chronicles
Waiting for you
Open
Your species
They appear in your campaigns' drop-downs and in Reference.
New species
Emberkin
Medium, 35 ft · My own work
EditDelete
Ashborn
Small, 30 ft · My own work
EditDelete
Approved for my campaigns
Your players' homebrew their characters may use. Withdraw stops new picks.
Wren’s Lucky Coin
Equipment item · player of Wren Ashdown · The Demo Chronicles
Approved
OpenWithdraw
The Homebrew page, with a tab for each of the nine kinds
Make or change an entry
Choose a tab, press New to make one, or Edit to change one. A change reaches every character already using it.
Your spells
They appear in your campaigns' drop-downs and in Reference.
New spell
Cinder Lance
1st level, Evocation · My own work
EditDelete
Call Ember Drake
1st level, Evocation · My own work
EditDelete
Ashfall
3rd level, Evocation · My own work
EditDelete
The Spells tab, with New to make one and Edit to change one
Where your homebrew shows up
Your homebrew belongs to your account, not to one campaign. So everything here can be picked in every campaign you run, by you and your players: in the character creator, on the sheet, in a level-up, and in Reference, where it carries a Homebrew badge.
Yours, not one campaign’s
Picked in every campaign you run, by you and your players:
The character creator
The character sheet
Level up
Reference
Cinder Lance
Evocation
Level 1
Homebrew can be picked in every campaign you run
Monsters
Monsters are yours alone. They turn up in your NPC and combat pickers, and in Reference.
Your monsters
They appear in your NPC and combat pickers and in Reference. Only you can see them, unless you tick Players can pick: then your players can choose one as a companion or Wild Shape form.
New monster
Ember Wisp
CR 1/4 · Tiny elemental · My own work
EditDelete
Cinder Drake
CR 3 · Medium dragon · My own work
EditDelete
Ash Hound
CR 0 · Medium beast · My own work
EditDelete
The Monsters tab
Your players can't make monsters, and only see one if you tick Players can pick this as a companion or form. Then they can choose it for a companion, or a Wild Shape. Monsters, equipment and magic items can also go into the generators: just tick Include in generators.
On the form
A monster
Players
Your homebrew monsters are hidden from players, so they stay a surprise.
✓ Players can pick this as a companion or form
Then players in your campaigns can see it, and choose it where their spells or features allow (a familiar, a Wild Shape form). Off by default.
Monsters, equipment and magic items
Include in generators
The two ticks on a monster's form
Delete, retire and bring back
To get rid of an entry, press Delete. If nothing uses it, it's gone. If a character, an NPC, a fight or another homebrew entry uses it, it's retired instead. It leaves every list, so nothing new can pick it, but it keeps working wherever it's already used.
Retired entries wait at the foot of the list. Press Bring back to return one.
Your monsters
They appear in your NPC and combat pickers and in Reference. Only you can see them, unless you tick Players can pick: then your players can choose one as a companion or Wild Shape form.
New monster
Ash Hound
CR 0 · Medium beast · My own work
EditDelete
Retired
Not offered in the pickers or the generators. NPCs and fights already using them keep them.
Cinder Drake
CR 3 · Medium dragon
Bring back
A retired monster at the foot of the list, with Bring back
Your players' homebrew
Your players can make homebrew too, and ask you to approve it. That's under Waiting for you, and it has its own guide: Approving your players' homebrew. So does each of the nine kinds.
Waiting for you · 1
Homebrew your players have asked you to approve. Open one to read it and answer.
Wren’s Spark
Spell · player of Wren Ashdown · The Demo Chronicles
Waiting for you
Open
Waiting for you, with one player's spell to approve
That's homebrew in Critsmith. If the game doesn't have it, make it, and it fits right in.