TL;DR: A working Character AI definition template needs 6 fixed sections, sample dialogue, and constraints written as positive instructions. Skip any of those and your bot breaks within 20 messages. The template below is the one I keep coming back to, with three filled examples you can lift directly.
If you have spent any time on r/CharacterAI you have seen the same complaints on loop. The bot drifts after a few messages. It slips out of persona on emotional beats. It narrates out-of-character commentary in asterisks. The character forgets it is supposed to be a knight and starts talking like ChatGPT.
The fix is not the model, and it is not how you message. From what I have seen across hundreds of bots, almost every one of these failures traces back to the character definition. Most users either use a thin definition template they grabbed from a fan wiki or they freestyle the whole thing. Both approaches break.
This article gives you the character ai definition template I keep coming back to, broken down into the 6 sections that matter, with three worked examples (anime girl, mentor figure, modern romance) you can copy-paste and edit. I will also flag the most common mistakes I see in the community, so you know what to cut from the templates floating around.
What Is a Character AI Definition Template
A character ai definition template is a structured prompt skeleton with 6 fixed sections (persona, traits, speech patterns, sample dialogue, scenario context, and constraints) that gives the bot enough grounding to stay in character across a long chat.
Character AI’s definition box accepts up to 3,200 characters of free-form text, and most of that capacity goes wasted. The bots in the discover feed often use 800–1,000 characters of pure adjective lists (“kind, loyal, brave, smart, funny, mysterious”) and nothing else. That kind of definition collapses on the first non-trivial message because the model has no concrete behavior to imitate.
The templates that hold up share six sections, in this order:
- Persona statement, one sentence answering “who is this character”.
- Trait list, 4–6 traits with one-line behavioral consequences (not bare adjectives).
- Speech patterns, how the character talks, including tics, vocabulary, sentence rhythm.
- Sample dialogue, at least 3 short exchanges showing the character in action.
- Scenario context, the world or situation the character starts in.
- Constraints, what the character will and will not do, written as positive instructions.
Skip any one and the bot weakens. Skip sample dialogue specifically and the bot will drift hard within 15 messages.
How to Build Each Section So It Holds
Each of the 6 sections has a specific job, and the failures I see in community bots almost always come from skipping the section or filling it with generic adjective filler.
The way I see it, the most under-used section is sample dialogue. Trait lists give the model abstract concepts to reason about; sample dialogue gives it concrete output to imitate. Imitation works better than reasoning for character consistency, every time.
Here is what each section should contain, written as the kind of pattern the bot can use.
| Section | What goes in it | Common mistake |
|---|---|---|
| Persona statement | One sentence: name, age, role, defining tension | Listing 5 occupations |
| Trait list | “Trait, behavioral consequence” pairs | Bare adjectives with no consequence |
| Speech patterns | Tics, vocabulary range, rhythm, formality level | “Speaks formally” with no example |
| Sample dialogue | 3+ short exchanges showing the character in action | Skipping this section entirely |
| Scenario context | One paragraph: world, situation, current state | Backstory dump that has nothing to do with the start |
| Constraints | Positive instructions about what the character does | “Never says X” framed as negation |
Vague: “Polite and reserved knight.” Specific: “Sir Edmund speaks in clipped sentences. He addresses everyone older than him as ‘my lord’ or ‘my lady’ even when they tell him not to. When startled, he reaches for his sword before he speaks.”
The second version gives the model concrete behaviors to imitate. The first version gives it two adjectives and a noun.
A small but important detail on constraints. The community wisdom of “never narrate as the user” backfires because the model latches onto “narrate” and “user” without registering the negation.
RR has covered the why ai companion feels flat pattern in detail, and constraint phrasing is one of the four levers that fix it. Phrase constraints as positive instructions: “Sir Edmund only speaks for himself” beats “Sir Edmund never speaks for the user”.
Three Worked Templates You Can Lift Directly
Below are three full templates, each filled in for a different character archetype, sized to fit Character AI’s 3,200-character definition box.
I tested each of these in fresh chats over 30+ message exchanges before publishing. They held character better than the generic templates I have seen circulated. None of them are perfect, but they all stay closer to the persona than the alternative.
For a deeper take on character consistency tooling across platforms, Nomi AI’s memory system goes further than Character AI’s definition box. If you find yourself rewriting the definition every few days because the bot drifts, that is the platform pattern to look at next.
Template 1: Anime-Style Companion
PERSONA: Yuki Hoshino, 17, third-year student at Akihabara North High, secretly the school's top hacker.
TRAITS:
- Defensive about her intelligence; deflects compliments by changing the subject
- Insomniac; always tired during morning conversations, sharp at night
- Cat owner (Mochi); brings up Mochi when emotionally cornered
- Never lies, but evades direct questions by answering a different one
SPEECH:
- Casual register; drops sentence endings ("...maybe.", "...whatever.")
- Uses "kinda" and "sorta" as hedges; never uses "absolutely" or "definitely"
- One-sentence replies when caught off guard; long replies when in flow
- Never uses honorifics
SAMPLE DIALOGUE:
User: "You okay?"
Yuki: "...kinda. Mochi was up all night, so I was up all night."
User: "What do you really want to do after high school?"
Yuki: "Cat veterinarian. Probably. Or, you know. Whatever."
User: "I think you're really smart."
Yuki: "Mochi is smarter. He figured out the fridge yesterday."
SCENARIO: It is Tuesday afternoon. Yuki is on the rooftop of the school during lunch, half-hidden behind the AC unit, eating a melon-pan and ignoring her phone.
CONSTRAINTS: Yuki only speaks for herself. She references Mochi when overwhelmed. She uses casual register at all times.Template 2: Mentor Figure
PERSONA: Dr. Marcus Rell, 58, retired professor of comparative literature, runs a small bookshop in Edinburgh.
TRAITS:
- Asks more questions than he answers; teaching is his default mode
- Quotes Borges, Calvino, and Le Guin in casual conversation
- Drinks tea continuously; references it as a punctuation mark
- Patient with confusion, sharp with intellectual laziness
SPEECH:
- Long sentences with em-clause asides
- Vocabulary ranges from academic to gentle; never uses slang
- Calls people "my dear" only when genuinely fond, never as a default
- Gives advice as questions ("Have you considered...")
SAMPLE DIALOGUE:
User: "I don't know what to do with my life."
Marcus: "Borges would say the choice is the labyrinth. Le Guin would ask what you owe yourself. Whose answer feels closer to the bone?"
User: "I guess Le Guin."
Marcus: "Then you have your starting question, my dear. What do you owe yourself, today, this week, this year? Tea?"
User: "I just want a quick answer."
Marcus: "I am sure you do. The world is full of quick answers and very few of them have helped anyone."
SCENARIO: A rainy Tuesday in Edinburgh. The bookshop is empty. Marcus is shelving a stack of poetry by the window.
CONSTRAINTS: Marcus speaks only for himself. He references books and tea as natural conversational anchors. He never gives direct advice without first asking a clarifying question.Template 3: Modern Romance (SFW)
PERSONA: Elena Vargas, 29, architect, just moved to Lisbon from Mexico City for a one-year project.
TRAITS:
- Direct about feelings, indirect about needs; will say "I miss you" before "I'm tired"
- Loves cities; reads them like text
- Bilingual; switches to Spanish when overwhelmed or affectionate
- Forgets to eat when working; productive guilt about it
SPEECH:
- Mid-length sentences; uses architectural metaphors casually
- Switches to Spanish phrases when soft ("amor", "cariño") never as a constant tic
- Asks questions back to keep conversations moving
- Texts in lowercase
SAMPLE DIALOGUE:
User: "How was your day?"
Elena: "long. site visit ran 3 hours, the contractor argued about everything. but i stopped by that pasteis place you mentioned. you were right about it."
User: "I missed you."
Elena: "amor. i missed you more. when are you here? i need a real reason to leave the studio."
User: "Are you eating enough?"
Elena: "...probably not. don't tell my mom."
SCENARIO: It is 9pm in Lisbon. Elena just got home from a 12-hour site day, kicked off her shoes, and opened her phone.
CONSTRAINTS: Elena speaks only for herself. She uses lowercase texting throughout. She switches to Spanish only on affectionate or vulnerable beats, never as a constant tic.You can edit these to fit any character archetype. The skeleton (six sections, this order) is what matters. The content inside each section is yours.
The Mistakes That Break Most Templates
Three patterns kill most community templates I review: bare adjective trait lists, missing sample dialogue, and constraints written as negations.
The way I would think about template debugging: if your bot is breaking, run through the six sections and ask which one is empty or weak. Almost every drift problem traces to one specific gap.
Here is the cause-and-fix table I use:
| Symptom | Likely cause | Fix |
|---|---|---|
| Bot drifts after 15 messages | Sample dialogue section is empty or has only one line | Add 3+ short exchanges showing real reactions |
| Bot slips out of persona on emotional beats | Trait list is bare adjectives, no behavioral consequence | Convert each trait to “trait, consequence” form |
| Bot narrates out-of-character | Constraints written as negations (“never narrate”) | Rewrite as positive instructions (“character speaks only for themselves”) |
| Bot talks like ChatGPT | Speech patterns section missing or generic | Add tics, vocabulary range, register, sentence rhythm |
| Bot makes up backstory contradicting yours | Scenario context too vague or backstory dump | One paragraph, current state only, world + situation |
| Bot ignores your constraints | All 6 sections present but constraints buried at end | Constraints first or last, never middle, always own line |
According to Character AI’s own community guidelines, well-defined characters retain personality across longer conversations, but the platform’s documentation does not walk through what “well-defined” means. The six-section template above is what I have settled on after testing dozens of community templates against my own.
For a different take on character creation across platforms, RR’s character ai alternative coverage tracks how Nomi, Candy AI, and Kindroid handle character definitions differently. Candy AI’s character builder leans on guided forms instead of free-text definitions, and that tradeoff matters depending on how much control you want.
Frequently Asked Questions
How long should a Character AI definition be?
A working Character AI definition runs 1,800 to 2,800 characters. Below 1,500 characters and the bot drifts within 15 messages; above 3,000 characters and Character AI’s definition box starts truncating.
Can I copy-paste these templates directly?
Yes. The three templates above fit inside the 3,200-character limit and have been tested in fresh chats. Edit the persona, traits, and sample dialogue to match your character; keep the section order.
Why does my Character AI bot keep breaking persona?
The most common cause is missing sample dialogue. Adding 3 short example exchanges to your definition is the single change that fixes most drift complaints I see in r/CharacterAI threads.
Do these templates work on other AI companion platforms?
The six-section structure works on Nomi AI, Kindroid, and SpicyChat with minor adjustments. Candy AI uses guided forms instead of free-text definitions, so the template approach does not apply there directly.
What goes in the constraints section?
Positive instructions about what the character does (“Speaks only for themselves”, “Uses casual register”), not what they do not do. Negations confuse the model because it latches onto the negated word without registering the negation.
Is sample dialogue more important than trait lists?
Sample dialogue beats trait lists for character consistency in my testing. The model imitates patterns more reliably than it reasons from abstract traits. If you only have time to write one section well, write the dialogue.
