Built the foundational rules engine — a pure Python library with zero AI dependencies. Fully deterministic given fixed random seeds. This is the bedrock everything else sits on.
The engine covers:
- Dice — rolling with advantage/disadvantage, rerolls, modifiers
- Ability scores and modifiers for all six stats
- Skill checks and saving throws with proficiency
- Initiative and turn order
- Attacks and damage — melee, ranged, with critical hits
- Action economy — action, bonus action, reaction, movement, free interaction
- All 15 SRD conditions plus exhaustion levels
- Death saving throws with every edge case
- Movement and opportunity attacks
- Spellcasting — slot management, concentration tracking, spell effects
- Character creation — 9 SRD races, 4 classes (Fighter, Rogue, Cleric, Wizard)
- Encounter building and difficulty calculation
Built on SRD 5.1 (CC-BY-4.0). 18 known edge cases that AI DMs always get wrong are explicitly handled and tested — things like how grapple interacts with prone, or what happens when you heal an unconscious creature that has failed death saves.