Unity Game AI Dialogue Engine

Dynamic NPC Dialogue • Context Memory • Intent System • Quest Hooks

Created and maintained by Unity King
https://unityking.com

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Quick Start (Important – Read First)

This repository contains only the Assets/ folder with a complete AI-powered Dialogue Engine.

How to Use This Repository

1. Create or open a Unity project

   • Unity 2021 LTS or newer recommended

2. Copy the Assets folder from this repository
   Paste it into your Unity project root

3. Open Unity

   • Scripts will auto-import

4. Add Dialogue components to your NPCs

   • Setup explained below

You are now ready to use the Dialogue Engine.

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📁 Project Structure

Assets/
├── Scripts/
│    ├── DialogueAI/
│    │    ├── Core/
│    │    │    ├── DialogueController.cs
│    │    │    ├── DialogueContext.cs
│    │    │    └── DialogueMemory.cs
│    │    ├── IntentSystem/
│    │    │    ├── DialogueIntent.cs
│    │    │    ├── IntentClassifier.cs
│    │    └── IntentResponse.cs
│    │    ├── Nodes/
│    │    │    ├── DialogueNode.cs
│    │    │    ├── DialogueOption.cs
│    │    │    └── DialogueGraph.cs
│    │    ├── QuestHooks/
│    │    │    ├── QuestTrigger.cs
│    │    │    └── DialogueQuestBridge.cs
│    │    └── UI/
│    │         └── DialogueUIController.cs

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System Overview

The Dialogue Engine is built on four core systems:

Dialogue Controller

Controls dialogue flow and NPC interaction lifecycle.

Context & Memory System

Remembers:

• Player choices
• NPC relationships
• Past dialogue events
• Quest states

Intent System

Understands what the player means, not just what they click:

• Greeting
• Asking for help
• Threatening
• Accepting / rejecting quests

Quest Hooks

Dialogue directly affects:

• Quest start
• Quest progression
• Quest completion

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Core Components Explained

DialogueController

Main entry point for NPC dialogue.

Responsibilities:

• Start / end dialogue
• Route dialogue nodes
• Communicate with UI
• Update memory & quests

DialogueController controller;
controller.StartDialogue(player);

Attach this to NPC GameObjects.

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DialogueContext

Stores runtime context:

• Current NPC
• Current node
• Player state
• World flags

context.currentNode
context.currentSpeaker

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DialogueMemory

Persistent memory system.

Stores:

• Player choices
• Flags (helpedNPC, betrayedNPC, etc.)
• Relationship values

memory.SetFlag("HelpedVillager", true);

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Intent System

The Intent System allows natural-feeling dialogue.

DialogueIntent

Represents an intent like:

• Greet
• AskForQuest
• Threaten
• Goodbye

IntentClassifier

Maps player input or options to intents.

IntentType result = classifier.Classify(input);

This allows:

• Dynamic responses
• AI-driven dialogue logic
• LLM integration later

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Dialogue Nodes & Graph

DialogueNode

Represents a single dialogue state.

DialogueNode
{
    text: "Hello traveler",
    options: [...]
}

DialogueOption

Player choices that:

• Change context
• Trigger intents
• Fire quests

option.nextNodeId
option.intent

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Quest Integration

QuestTrigger

Hooks dialogue to quest logic.

Examples:

• Start quest on dialogue
• Complete quest on choice
• Fail quest on threat

QuestTrigger.TriggerQuest("FindTheSword");

DialogueQuestBridge

Connects Dialogue Engine with your Quest System.

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Dialogue UI

DialogueUIController

Handles:

• Showing dialogue text
• Rendering options
• Player input

Framework is UI-agnostic:

• Unity UI
• TMP
• Custom UI systems

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Example NPC Setup

1. Create NPC GameObject

2. Add:

   • DialogueController
   • DialogueUIController

3. Assign:

   • DialogueGraph
   • Memory reference

4. Press ▶ Play

NPC will:

• Remember player
• React to choices
• Trigger quests

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Extending the System

You can easily add:

• Voice acting
• Relationship systems
• LLM / AI text generation
• Morality systems
• Branching storylines

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Use Cases

• RPGs
• Adventure games
• Story-driven games
• AI NPC experiments
• LLM-powered dialogue

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License

MIT License Free for personal & commercial use.

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Author

Unity King https://unityking.com Game AI • Systems • Tools

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