storybook/docs/tutorial/02-creating-characters.md

Creating Characters

Characters are the heart of every Storybook world. In this chapter, you will learn how to define characters with fields, prose blocks, species, and templates.

A Simple Character

The simplest character has a name and some fields:

character Martha {
    age: 34
    skill_level: 0.95
    is_open: true
}

Fields use the name: value format. Storybook supports several value types:

Type	Example	Description
Integer	42	Whole numbers
Float	0.85	Decimal numbers
String	"hello"	Text in double quotes
Boolean	true / false	Yes or no values
Time	14:30	Clock times
Duration	2h30m	Time intervals
List	[1, 2, 3]	Ordered collections

Adding Descriptions with Prose Blocks

Prose blocks embed narrative text directly alongside data. They start and end with --- and have a tag name:

character Martha {
    age: 34
    skill_level: 0.95

    ---backstory
    Martha learned to bake from her grandmother, starting at age
    twelve with simple bread recipes. She mastered sourdough and
    pastries, eventually opening the most popular bakery in town.
    ---

    ---appearance
    A confident woman in her mid-thirties, usually dusted with
    flour. Her hands are calloused from years of kneading dough.
    ---
}

You can use any tag name you like. Common ones include backstory, appearance, personality, motivation, and secrets.

Defining Species

Species define what a character fundamentally is. Define them separately, then reference them with the : syntax:

species Human {
    lifespan: 70

    ---description
    Bipedal mammals with complex language and tool use.
    ---
}

species Cat {
    lifespan: 15

    ---description
    Domestic cats make loyal companions and effective
    pest control for bakeries.
    ---
}

Now use species when creating characters:

character Martha: Human {
    age: 34
}

character Whiskers: Cat {
    friendly: true
    catches_mice: true
}

The : Human part says "Martha is a Human." She inherits the species' fields (like lifespan: 70) automatically.

A character can have only one species -- you cannot be both Human and Cat.

But what about hybrids?

If you want a character that combines traits from different sources, use composition with templates instead:

species Human {
    lifespan: 70
    reasoning_ability: 1.0
}

template CulinaryExpert {
    palate_sensitivity: 0.5..1.0
    recipes_mastered: 0..500
    can_identify_ingredients: true
}

template BusinessOwner {
    business_acumen: 0.0..1.0
    manages_finances: true
    leadership: 0.0..1.0
}

// A character combining species with multiple templates
character Martha: Human from CulinaryExpert, BusinessOwner {
    age: 34

    // From CulinaryExpert
    palate_sensitivity: 0.9
    recipes_mastered: 150
    can_identify_ingredients: true

    // From BusinessOwner
    business_acumen: 0.8
    manages_finances: true
    leadership: 0.85

    // Unique traits
    specialty: "sourdough"
    years_experience: 22

    ---personality
    A perfectionist in the kitchen who demands the best from her
    ingredients and her team. Warm with customers but exacting
    with her apprentices.
    ---
}

By combining a species with templates, you can achieve any combination you need. The species defines what the character fundamentally is, while templates add traits from other sources.

Reusing Traits with Templates

Templates define reusable sets of attributes. Characters inherit from them using the from keyword:

template SkilledWorker {
    skill_level: 0.0..1.0
    years_experience: 0..50
}

template Baker {
    include SkilledWorker
    specialty: "general"
    recipes_mastered: 0..500
}

Notice the 0.0..1.0 syntax -- that is a range. When a character uses this template, a specific value within that range is selected. Ranges are only valid in templates.

Characters can inherit from multiple templates:

character Martha: Human from Baker, BusinessOwner {
    age: 34
    skill_level: 0.95
    specialty: "sourdough"
    recipes_mastered: 150
}

The from Baker, BusinessOwner part says "Martha has the traits from both templates." You can override any inherited field by specifying it directly.

Species vs. Templates

Understanding the difference is important:

	Species (:)	Templates (from)
Meaning	What the character is	What the character has
Count	Exactly one	Zero or more
Example	: Human	from Baker, BusinessOwner

Think of it this way: a character is a Human, but has baking skills and business acumen.

Field Resolution

When a character inherits from multiple sources, fields are resolved in priority order:

1. Species fields (lowest priority)
2. Template fields (left to right in the from clause)
3. Character fields (highest priority -- always wins)

species Human {
    speed: 1.0
}

template Warrior {
    speed: 1.5
    strength: 10
}

template Berserker {
    speed: 2.0
    strength: 15
}

character Conan: Human from Warrior, Berserker {
    strength: 20
}
// Resolved: speed = 2.0 (Berserker), strength = 20 (Conan)

Using Enums for Controlled Values

Enums define a fixed set of named values. They prevent typos and ensure consistency:

enum SkillLevel {
    Novice,
    Beginner,
    Intermediate,
    Advanced,
    Expert,
    Master
}

enum Specialty {
    Sourdough,
    Pastries,
    Cakes,
    Bread,
    Confections
}

Use enum values as field values:

character Martha: Human {
    skill_level: Master
    specialty: Sourdough
}

If you write skill_level: Professional, the compiler will catch the mistake because Professional is not defined in the SkillLevel enum.

Importing Across Files

Real projects split definitions across multiple files. Use the use statement to import:

// In world/characters/martha.sb
use schema::core_enums::{SkillLevel, Specialty};
use schema::templates::Baker;
use schema::beings::Human;

character Martha: Human from Baker {
    skill_level: Master
    specialty: Sourdough
}

The use schema::core_enums::{SkillLevel, Specialty} line imports two enums from the schema/core_enums.sb file. You can also import everything with use schema::core_enums::*.

Putting It All Together

Here is a complete character definition with all the features:

use schema::core_enums::{SkillLevel, Specialty};
use schema::templates::{Baker, BusinessOwner};
use schema::beings::Human;

character Martha: Human from Baker, BusinessOwner {
    // Core identity
    age: 34
    skill_level: Master
    specialty: Sourdough

    // Professional
    years_experience: 22
    recipes_mastered: 150
    can_teach: true

    // Business
    business_acumen: 0.8
    leadership: 0.85

    ---backstory
    Martha learned to bake from her grandmother, starting at age
    twelve with simple bread recipes. She mastered sourdough and
    pastries, eventually opening the most popular bakery in town.
    ---

    ---personality
    A perfectionist in the kitchen who demands the best from her
    ingredients and her team. Warm with customers but exacting
    with her apprentices. Known for arriving at 4 AM to start
    the morning batch.
    ---
}

Next Steps

Now that Martha exists, let us give her something to do. In Your First Behavior Tree, you will learn how characters make decisions.

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Reference: For complete character syntax details, see the Characters Reference.