Built an AI dungeon master using GPT-4o with memory

I built AI Dungeon Master — a text-based RPG powered by GPT-4o with persistent world state and character memory.

Key features:

Persistent world state stored in a JSON "world model"

Character sheets with stats, inventory, and relationships

Combat system with dice mechanics

The AI maintains narrative consistency across 50+ turns

The trick to consistency is feeding a compressed world state as context:

{
  "location": "Dark Forest - clearing near the river",
  "time": "dusk, day 3",
  "party": [
    {"name": "Elara", "class": "ranger", "hp": 24, "status": ["poisoned"]}
  ],
  "active_quests": ["Find the missing merchant"],
  "recent_events": ["Defeated 3 goblins", "Found mysterious map"]
}

The world model gets updated after each turn using structured outputs. Users are loving it — average session is 45 minutes!