# How to Write an AI Character That Stays in Character > A practical method for writing an AI character: three traits and one contradiction, a scene instead of a backstory, and a first message that sets the voice. - Published: 2026-10-14 - Updated: 2026-10-14 - Author: SecretCrush AI Editorial - Category: Guides - Canonical URL: https://secretcrush.ai/blog/how-to-write-an-ai-character ## The short answer A character stays in character when the model has three things to work from: a small number of traits that pull against each other, a scene that is already in motion, and a first message written in the character's own voice. Long backstories and lists of rules do less than people expect, and often make things worse. The rest of this guide walks through each part, gives a filled example, and shows where each piece goes in the [SecretCrush AI character builder](https://secretcrush.ai/create/character). > **Coming from Character.AI?** > > A Character.AI character has a long definition and a greeting of up to 4,096 characters; most other apps give you far less room. Our guide to [moving a character from Character.AI](https://secretcrush.ai/blog/move-characters-from-character-ai) shows what you can save there today and how to rewrite each field, with a filled example. ## What the model actually reads A chat model does not know your character the way you do. On every turn it reads a block of text and writes what plausibly comes next. That block is roughly: the character's description, the scenario, the conversation so far, and your latest message. Two consequences follow. **The conversation outweighs the description.** After twenty messages there is far more chat than character sheet in what the model reads. If the early replies sound generic, later ones copy them. This is why the first message matters so much: it is the first sample of the voice. **Long chats get summarised.** No app sends the full history forever. Many keep a running summary plus the most recent messages. A detail that only ever appeared in one line forty messages ago may not survive the summary. Traits that show up in how the character speaks survive, because they are in every reply. So the job is not to tell the model everything. It is to give it a few things it can keep doing. ## Personality: three traits and one contradiction Pick three traits. More than that and none of them leads; the character averages out into "friendly". Then add one thing that pulls against them. A confident character who goes quiet when complimented. A caring one who cannot stand being fussed over in return. The contradiction is what gives the model a choice to make in each reply, and choices are what read as a person. Make each trait something you could see or hear: - Instead of "witty", write how it shows: answers a question with a better question, never laughs at her own jokes. - Instead of "shy", write what she does: talks to the thing in her hands, finishes sentences a beat late. - Instead of "caring", write the habit: remembers what you ate yesterday and has opinions about it. In the builder, the personality row offers one-word options such as Sweet, Playful, Witty, Confident, Mysterious and Intellectual, or you can type your own in up to 30 characters. One word is a label, so carry the detail into the scenario and first message, where you have room. ## Scenario: where, when, what just happened The most common mistake is writing a biography: where she grew up, her last three jobs, her family. The model reads all of that as things to talk *about*, and you get a character who narrates her past instead of being in the room with you. A character built from backstory often reads as if she is somewhere else. Write a scene instead. Three questions cover it: 1. **Where and when?** One place, one time of day. "Her restaurant kitchen, twenty minutes after closing." 2. **What just happened?** Something small and recent. "The last table sent back a full plate and she is still annoyed." 3. **What does each of you want right now?** Wants create movement. "She wants a second opinion on the dish. You came to return her spare key." Notice that backstory still gets in, as much as the scene needs: she owns a restaurant, you are neighbours, she is a perfectionist. It arrives as a situation instead of a list. The builder's Scenario field has the hint "Where and how the chat begins" and holds up to 512 characters. That limit is a feature. If the scene does not fit, it is two scenes. ## The first message does half the work The first message is the opening line you receive from the character. It is also the model's best example of how she talks, how long her replies are, and how much is description against speech. Whatever it does, the next fifty replies will tend to do. A first message that works: - **Is in the scene.** It starts where the scenario left off, mid-action. - **Shows the traits.** If she is witty, there is a dry line in it. If she is guarded, something is held back. - **Is the length you want back.** Three sentences in gets about three sentences out. - **Ends on something to answer.** A question, an offer, an object held out. Give yourself an easy first reply. - **Does not speak for you.** It should not describe what you say, think or feel. The First message field in the builder also holds up to 512 characters. ## A filled example Here is a complete character, written to fit the builder's fields. She is an adult in an adult setting, and nothing here needs more than the fields provide. - **Name:** Nora - **Age:** 31 - **Personality:** Witty - **Occupation:** Chef - **Relationship:** Neighbor - **Hobby:** Hiking **Scenario** (342 characters): ``` Nora's small restaurant, twenty minutes after closing. You live across the hall from her and came down to return her spare key. The last table sent a plate back untouched and she has been remaking the dish ever since. She is quick and dry with everyone, and goes quiet when someone is kind to her. She wants a second opinion and will not ask. ``` **First message** (274 characters): ``` *She doesn't look up from the pan.* "Key goes on the hook. And before you say anything, yes, I know we're closed." *She slides a fork across the counter toward you.* "Sit. Table nine says this is too salty. Table nine is wrong, but I'd like to hear it from someone I trust." ``` What the example does: the three traits are quick, dry and proud; the contradiction is that kindness disarms her. The scene has a place, a recent event and a want on each side. The first message shows the voice, sets the reply length, and hands you a fork, which is an easy thing to respond to. Paste in Nora, or write your own, and see how she plays. The character builder is free on a free account. [Create your character](https://secretcrush.ai/create/character) ## Five common mistakes 1. **A biography instead of a scene.** Covered above. Cut the history to what the present needs. 2. **A wall of rules.** "Never do this, always do that" makes replies rigid and samey. Keep one or two rules at most and describe the person instead. 3. **Adjectives only.** "Kind, funny, smart, loyal" describes everyone. Show one habit per trait. 4. **A first message that is a greeting.** "Hi, how are you?" teaches the model to make small talk. Start mid-scene. 5. **Writing the user's side.** If the first message says what you feel, the character will keep deciding that for you. ## Build it in SecretCrush AI The [character builder](https://secretcrush.ai/create/character) has six steps: Style, Ethnicity, Face, Body, Personality and Review. Every step starts with something already chosen, so you can move quickly through the ones you do not care about. - **Style to Body** set the look from picture cards. You can also describe the appearance in your own words, in up to 300 characters, and that description takes priority over the picks. - **Personality** is where you set the name (up to 30 characters), the age (18 or over) and the rows for personality, occupation, relationship and hobby. Each row is a list with an "Or type your own" box. This step also makes the character's photo, which costs 6 coins. A new account's 20 welcome coins cover it. - **Review** has the Story section. Choose "AI writes it" and the scenario and first message are written from your picks, or choose "I write it" and fill in both fields yourself. In that mode a "Draft with AI" button will write a draft, or expand what you have typed, for you to edit. Free accounts get 15 AI suggestions a day. You can go through the steps before signing in; an account is needed when you create the photo, and a free account is enough. Paste in the Nora example above to see how it plays, or start your own: **[open the character builder](https://secretcrush.ai/create/character)**. Characters you make are private by default. For ideas, browse [original characters](https://secretcrush.ai/tag/original-character) and [scenario-led characters](https://secretcrush.ai/tag/scenario) and look at how their openings are written. Once the character talks the way you want, the next step is keeping her looking the same from picture to picture, which is covered in [consistent AI character images](https://secretcrush.ai/blog/consistent-ai-character-images). A well-written character is only half of it; the other half is a chat that does it justice. SecretCrush AI is built for immersive, realistic roleplay, and a free account gets 10 messages every day. Premium adds unlimited messages with advanced memory, premium models, AI images and videos of your character in the chat, and 500 bonus coins every month, from $8.99 a month on the yearly plan; see the [pricing page](https://secretcrush.ai/pricing). Three traits, one scene and a first message: that is all it takes. Build your character on SecretCrush AI tonight, no card needed. [Build your character free](https://secretcrush.ai/create/character) ## FAQ **Q: How long should an AI character description be?** A: Short. On SecretCrush AI the scenario and the first message are limited to 512 characters each, and that is enough. A few specific lines the model can act on beat a page of history it has to summarise. **Q: Why does my AI character forget its personality?** A: Usually because the personality was stated as labels and never shown. Put the traits into the first message, so the character's voice is in the conversation itself, and give it a scene with something to want. **Q: Should I write rules like 'never break character'?** A: Sparingly. A list of rules tends to make a character stiff and repetitive, because the model treats every reply as a test of the rules. Describe who the character is and what is happening, and keep rules for the one or two things that really matter. **Q: What is the difference between a scenario and a backstory?** A: A backstory is what happened before. A scenario is where the two of you are right now and what just happened. The model plays the present, so the scenario does most of the work. **Q: Can I change a character after creating it?** A: On SecretCrush AI, yes. The builder says the scenario and first message can be changed at any time under My characters.