RPG backend engine designed as a game logic API for Godot UI integration. Implements CQRS pattern with MediatR for clean command/query separation.

Vertical Slice + CQRS with MediatR

Three core libraries:

• RealmEngine.Core - Game logic (combat, inventory, crafting, quests)
• RealmEngine.Data - JSON data loading, persistence (LiteDB)
• RealmEngine.Shared - Models, utilities, abstractions

RealmForge - Separate MAUI tool for editing JSON game data (on hold).

Code organized by business feature (Features/Combat, Features/Inventory, etc.) with automatic validation and logging via MediatR pipeline behaviors.

Backend API for Godot UI - This repository contains zero production UI code.

// Godot calls backend via MediatR
var result = await mediator.Send(new AttackEnemyCommand 
{ 
    CharacterName = "Player1",
    Action = CombatActionType.Attack 
});

// Godot receives DTO and updates UI
if (result.Success) {
    UpdateHealthBar(result.PlayerHealth);
    ShowDamageNumber(result.Damage);
}

# Build engine (no MAUI required)
dotnet build RealmEngine.sln

# Run test suite
dotnet test RealmEngine.sln

# VS Code debug
Press F5

Game Mechanics

• D20 system with 6 attributes (STR/DEX/CON/INT/WIS/CHA) and derived stats
• 6 character classes with unique bonuses and progression paths
• Turn-based combat with dodge/crit/block mechanics
• Interactive level-up with attribute allocation
• Skill system (8 skills enhancing combat/abilities)
• Status effects (poison, stun, burning, shield, regeneration)

Content Systems

• Item generation with budget-fitting algorithm (5 rarity tiers)
• Tiered crafting system with quality bonuses and failure mechanics
• Material reference system (JSON v4.1) for data reuse
• Quest system with objectives and rewards
• Spell system with mana management
• Shop/economy with dynamic pricing
• Procedural enemy generation with difficulty scaling

Data & Persistence

• 211 JSON data files (enemies, items, abilities, spells, materials)
• JSON v5.1 standards with cross-reference system (@domain/path:item)
• LiteDB save/load with auto-save support
• Budget-based item costing using rarityWeight inverse formula

Integration

• MediatR commands/queries for all game operations
• Event-driven architecture for game state changes
• Structured logging (Serilog) with exception tracking
• Validation pipeline (FluentValidation) for all inputs

Comprehensive test suite across three test projects:

• RealmEngine.Data.Tests - JSON compliance, reference integrity, data validation
• RealmEngine.Core.Tests - Combat, crafting, inventory, quests, character progression
• RealmEngine.Shared.Tests - Models, utilities, services

# Run all tests
dotnet test RealmEngine.sln

# Run specific test projects
dotnet test RealmEngine.Data.Tests
dotnet test RealmEngine.Core.Tests
dotnet test RealmEngine.Shared.Tests

Core Libraries

• MediatR 14.0.0 - CQRS command/query pattern
• LiteDB 5.0.21 - NoSQL persistence
• Newtonsoft.Json 13.0.4 - JSON data loading
• FluentValidation 12.1.1 - Input validation
• Serilog 4.3.0 - Structured logging
• Polly 8.6.5 - Resilience patterns

Utilities

• Bogus 35.6.5 - Procedural content generation
• Humanizer 3.0.1 - Natural language formatting

Testing

• xUnit 2.9.3 - Test framework
• FluentAssertions 8.8.0 - Test assertions

RealmEngine/
├── RealmEngine.Core/           # Game logic and MediatR handlers
│   ├── Features/               # Vertical slices (Combat, Crafting, Inventory, etc.)
│   ├── Generators/             # Procedural content generation
│   └── Services/               # Core game services
├── RealmEngine.Data/           # Data access and JSON loading
│   ├── Data/Json/              # Game data files
│   └── Services/               # Data services and repositories
├── RealmEngine.Shared/         # Shared models and utilities
│   ├── Models/                 # Domain models
│   └── Abstractions/           # Interfaces and base classes
└── [Project].Tests/            # Test projects

• RealmEngine.sln - Core engine only (no MAUI dependencies, CI/CD builds)
• RealmForge.sln - MAUI data editor tool (requires MAUI workloads)
• RealmEngine.Full.sln - All projects for local development

• Game Design Document - Complete game specification
• Commands and Queries Index - All MediatR commands/queries
• API Specification - Backend API for Godot integration
• JSON Standards - JSON v5.1 data file standards
• Implementation Status - Feature completion tracking
• Documentation Index - Complete documentation list

Platform: .NET 9.0 | Pattern: CQRS with MediatR | UI: Godot (separate) | Data: LiteDB + JSON