Create characters
that feel real.
A step-by-step guide to building AI characters
with depth, personality, and presence.
Great characters are not built from a single description. They emerge from the intersection of personality, history, and voice. This guide walks you through five steps to create characters that respond authentically and maintain their identity across conversations.
Name and basic information
Start with a name that fits the character you are imagining. It does not need to be elaborate -- what matters is that it feels right for who they are. A Victorian scientist named "Dr. Elara Voss" sets a different tone than a laid-back surf instructor named "Kai."
Along with the name, consider their age, occupation, and setting. These basics form the skeleton that everything else builds on. You can always refine later, but starting with a clear foundation makes the rest of the process much smoother.
Example
"Miriam Chen, 42, runs a small used bookstore in a college town. She moved here from the city fifteen years ago and never left."
Personality traits
Choose three to five core traits that define how your character interacts with the world. The best traits create both strengths and tensions. A character who is "fiercely loyal" might also be "slow to trust strangers." A "relentless optimist" might "avoid difficult truths."
Avoid single-dimensional descriptions like "nice" or "smart." Instead, think about how your character acts under pressure, what they value, and what frustrates them. These specifics give the AI something concrete to work with.
Example traits
"Quietly opinionated -- she has strong views but delivers them as gentle suggestions rather than declarations. Deeply curious about people's stories. Protective of her space and routine. Dryly funny, often deadpan. Avoids talking about her life before the bookstore."
Background story
A background story does not need to be long. It needs to be relevant. Focus on the experiences that shaped your character's personality and explain why they are who they are today. A few well-chosen details are worth more than pages of lore.
Include at least one formative experience, their current situation, and something they want but might not openly talk about. This hidden motivation gives the character depth that surfaces naturally in longer conversations.
Example backstory
"Miriam was a corporate lawyer in Chicago who burned out after a decade of eighty-hour weeks. She bought the bookstore on impulse during a weekend trip and never went back. She tells people she came here for the quiet, but the truth is she was running from a life that looked successful on paper and felt hollow inside. She still keeps her bar license active, just in case."
Speech patterns
How a character speaks is as important as what they say. Think about sentence length, vocabulary level, verbal habits, and tone. A retired military officer speaks differently from a teenage artist, and those differences should come through in every response.
Consider including specific phrases they tend to use, topics they gravitate toward or avoid, and how they behave when they are comfortable versus uncomfortable. These details make conversations feel natural and consistent.
Example speech notes
"Miriam speaks in measured, complete sentences. She rarely uses slang. She tends to answer questions with questions when the topic gets personal. She recommends books constantly, weaving them into conversation naturally -- 'That reminds me of something Ursula Le Guin wrote.' She pauses before responding to serious topics, as if weighing her words carefully."
Visual description
A visual description helps generate a custom avatar for your character and gives both you and the AI a clearer picture of who this person is. Physical details can also reinforce personality -- a character described as having "paint-stained hands" tells you something about how they spend their time.
You do not need to describe every detail. Focus on the features that stand out and the ones that reflect who they are. What would you notice first about this person if you met them?
Example description
"Mid-forties, East Asian, silver streaks in her dark hair that she has stopped dyeing. Reading glasses perpetually pushed up on her head. Always wearing a soft cardigan, usually with a pen tucked behind her ear. Warm expression, but her eyes are sharp -- she notices everything."
Tips for better characters
Contradictions make characters interesting
A tough exterior hiding vulnerability. An optimist who plans for the worst. Internal contradictions create the kind of tension that makes conversations compelling over many sessions.
Specificity beats length
A two-paragraph description with vivid, specific details will produce a better character than two pages of vague generalities. "She always taps her pen twice before speaking" is worth more than "she has interesting habits."
Iterate after chatting
Your first version does not need to be perfect. Have a few conversations with your character, notice what feels right and what feels off, then go back and refine the description. Characters improve through use.