# Building Characters | Lunafic Source: https://lunafic.ai/docs/building-characters | Published: 2026-08-26T04:00:16.517Z | Updated: 2026-10-09T03:41:35.483Z | Author: Lunafic Team | Tags: Private world > Characters the AI can play: series, nicknames, speech style, personality, speech examples, and knowledge scope. The World Bible, field by field. Every "the AI plays my character wrong" report we see traces back to the same place. The name and face are right and the voice comes out flat, polite where she should be sharp. The AI is not broken, it is under-taught. A character is a set of panels, and the AI plays exactly what the panels teach it. Fill them well and the voice holds for chapters. Leave them thin and the flattening starts within a scene. > > Speech style is how the AI would say something, and personality is how the AI would act. Most of the time, the mistakes come from lack of explanation in these two. It matters most for feelings, especially in language, and in Japanese. ## Speech Style, where the feelings live Personality says what a character does, and Speech Style says how they sound while doing it. Write it the way you would describe a voice to a voice actor, with sentence endings, verbal tics, rhythm, and words they would never use. It matters in every language. An English speaker can speak in short hard sentences, or in long ones that wander and double back. ## Personality Give three moods, in public, in private, and under pressure. One line is a mood and not a personality. The third mood is where scenes live. ## Speech Examples Lines of the character actually talking. This is the strongest teaching panel, and it works best when the lines are nothing alike, one calm, one angry, one teasing, one caught off guard. > > Minimum 5 lines. Five lines of the character actually talking teach the AI more than a paragraph of description. Steal them from the source if you have one; write them fresh if you do not. ## Knowledge What this character knows and what they do not. Write plain facts, like knows the ball happens every winter, or does not know who sent the letter. If your character knows someone only as the opera star, that is all the AI will use, however deep the other panels go. ## Nicknames Write who calls this character what, with the caller in brackets, like Emilia-tan (called by Subaru). The AI resolves the right name to the right mouth. ## Series The franchise the character comes from, for fanfiction. Leave it empty for original characters. ## The ten minute test - Write one scene. **A greeting, a question, a line of action.** - Read the reply. **Find where the voice went flat.** - Fix that panel, then write the scene again. **The panel fixes every future scene at once.** [More on keeping the Wiki lean is in the best practices page.](/docs/world-bible-best-practices) --- Read this on Lunafic: https://lunafic.ai/docs/building-characters More from Lunafic: https://lunafic.ai/docs What is Lunafic: https://lunafic.ai/ai-roleplay AI characters you build stories with over long memories. You play as your character, the AI plays everyone else, and stories stay private by default.