tdd

What problem does it solve? Multiplayer games built on deterministic lockstep with rollback desync when developers use wall-clock timers, unseeded randomness, or frame-driven simulation. This Skill is the ShatterLess repo's engineering law: it tells you exactly which architecture, conventions, and determinism rules to follow before writing or changing any Godot code. ## Core Features & Use Cases - Architecture & Stack Reference: Documents the Godot 4.7 + Forward Plus + D3D12 setup, the GDScript-over-C# decision, Rapier3D physics, netfox autoloads (NetworkTime, NetworkRollback, NetworkEvents), feature-folder repo layout, and typing/naming conventions. - Determinism & Netcode Rules: Defines the seven rules for P2P deterministic lockstep with rollback — simulation in _rollback_tick, banned wall-clock/RNG APIs, full state save/restore via RollbackSynchronizer, and fresh-tick-only input polling. - Known-Violations Fix Table: Tracks which debug scripts (player, bullet, destructible target) have been ported to rollback-safe simulation and how, so you don't reintroduce desyncs. - Use Case: Before adding a new weapon to the game, read the determinism reference to learn that ammo state must live in state_properties, reload deadlines must be tick counts, and firing must be driven by replicated input properties. ## Quick Start Ask the AI to review the tdd skill's determinism rules before implementing a new networked gameplay feature in the Godot project.