What Is a Lorebook? How AI Roleplay Lore Works

Why lorebooks exist

An AI model reads your chat through a window of fixed size. The app sends everything in a character's description with every message, so the description takes up room in that window for the whole chat. Chub's guide describes a lorebook as a way to give the AI backstory and setting "without needing to have it be in character definitions taking up permanent token space". Character AI made the same point when it launched its Lorebook in July 2026: until then, everything a character knew about its world had to fit inside its definition.

So the description holds who the character is, and the lorebook holds what the world contains. Each piece of lore stays out of the prompt until the story reaches it.

The name varies. SillyTavern calls the feature World Info and says it is also known as lorebooks or memory books. Chub calls a lorebook attached to a character a character book.

How a lorebook works

In Character AI, SillyTavern, NovelAI and Chub, lorebooks run on keywords. Each entry has two parts: the content, which is the text the AI will read, and a list of keywords. When one of the keywords appears in the recent conversation, the app adds that entry's content to what it sends the AI for the next reply. SillyTavern's documentation compares it to a dictionary that inserts an entry only when its keywords are present in the message text.

Here is an entry about an inn, made up for this guide:

Write "let's get a room at the Blackwater" and the AI receives those four sentences along with your message. In a scene set somewhere else the entry stays out and takes up no room.

Three settings decide which entries get in, and apps name them differently:

• How far back the app looks. Chub calls this scan depth: the number of recent messages it checks for keywords. NovelAI counts characters of story text instead, up to 10,000.
• How much lore fits at once. Chub and SillyTavern both set a token budget. Once the budget is used up, the app skips further entries even when their keywords match.
• How keywords match. Chub ignores capital letters and matches whole words by default, so the keyword "Apple" triggers on "apple" and not on "Applebottom". SillyTavern and NovelAI also ignore capital letters by default.

Some apps add options. You can set an entry to load every time, which NovelAI calls Always On and Chub calls Constant. SillyTavern and Chub can also let the text of one entry trigger another, which they call recursive scanning.

The AI reads only the content. SillyTavern does not insert an entry's title or keywords, and NovelAI says the title isn't visible to the AI. A loaded entry also doesn't force the reply: SillyTavern says World Info "does not guarantee" that the lore appears in the output, which depends on how well the model uses what it is given.

Lorebooks in five apps

From each app's own pages, read 12 November 2026 and linked under Sources. PersonaChat's row is from its Memory & Lore page and the app.

How to write a lorebook entry

• One subject per entry. A person, a place, an object, a faction or a rule. An entry that covers the inn, its owner and the city's politics loads all three when you only mention the inn.
• Name the subject in the content. The AI doesn't see the title, so "She owns the inn" tells it nothing and "Mara Venn owns the Blackwater Inn" tells it who and where. NovelAI's documentation gives the same advice.
• Keep it short. Every loaded entry uses part of the budget, and SillyTavern advises keeping entry contents concise. A few plain sentences of fact are enough.
• Choose keywords you will type. Use names, nicknames and the words a scene would use for the thing. A common word such as "door" or "king" loads the entry in scenes that have nothing to do with it, and that uses up the budget.
• Keep constant facts somewhere constant. A fact that must hold in every reply, such as how the character speaks, belongs in the character's description or in an always-on entry, because a keyword entry isn't in the prompt when its keyword hasn't come up.

Lorebook, character description or memory?

You write a lorebook on purpose. Memory is what an app keeps from the conversation itself, and apps handle that differently. Our guide to story memory explains how PersonaChat does it, and the character guide covers what belongs in a description.

Lorebooks on Character AI

Character AI announced Lorebook on 24 July 2026 as a beta, with early access for c.ai+ subscribers. It runs on keywords like the tools above: each entry has keywords, and when one comes up in conversation the character gets access to that entry. A creator can link one Lorebook to several characters so that a cast shares the same world, and characters with an active Lorebook carry a +Lore tag.

When we checked on 12 November 2026, Character AI's plan table listed Lorebook as Basic on the Free and lite plans and as Adv. on c.ai+. The table doesn't say what separates the two.

The Lorebook in PersonaChat

PersonaChat is an AI character chat app for iPhone and iPad, and its Lorebook is free on every plan. Its entries have no keywords: you write the fact, and PersonaChat compares each entry with your newest message, by meaning and by the words they share, and brings in the closest few. The advice on writing entries still applies, apart from choosing keywords. Name the subject and keep each entry to one subject, so that a message about the inn finds the inn.

• You add, edit and delete entries on the Memory & Lore screen. Each entry holds up to 512 characters.
• An entry can apply to one story or to every chat with that character.
• Living Memory keeps details from the chat automatically. You can save one of its memories into your Lorebook when you want to keep and edit it yourself.
• The Lorebook works in one-to-one chats. Group chats use the running recap.
• If you import a character card as a JSON file, a lorebook attached to the card doesn't come with it. Re-create the entries you need by hand.

The Memory & Lore page has the details, and our comparison with Character AI says where each app is stronger.

Write your first entry

Pick the one fact your story keeps getting wrong and write it down in two or three sentences. PersonaChat is free to start, with a running recap, Living Memory and a Lorebook on every plan.

★★★★★★★★★★ 4.4 on the App Store · Free to start

Sources

• World Info, SillyTavern Documentation, read 12 November 2026
• Lorebooks, Chub AI Guide, read 12 November 2026
• Lorebook, NovelAI Documentation, read 12 November 2026
• Introducing Lorebook: Build the World Behind Your Characters, Character.AI, 24 July 2026
• Character.AI plan table, read 12 November 2026

Frequently asked questions