---
tags:
- design
- index
updated: 2026-05-29
permalink: gamevault/02-game-design/systems-index
---

# Systems Design — Index

One design doc per gameplay system, linked here. Each should state: purpose, components (`IComponentData`), systems (`ISystem`), netcode shape (ghost? predicted vs interpolated? inputs / RPCs), and open questions.

## Systems

### M1 — Player (twin-stick predicted movement) · [[2026-05-30_M1_Player_Slice]]

- **Components** (`ProjectM.Simulation`): `PlayerTag`; `PlayerInput` (IInputComponentData — `float2` Move/Aim, `[GhostField]`, flows via AutoCommandTarget); `PlayerMoveStats` (baked tunables); `PlayerFacing` (`[GhostField]` Direction); `PlayerSpawner` (baked prefab singleton); `GoInGameRequest` (IRpcCommand).
- **Systems:** `PlayerMoveSystem`, `PlayerAimSystem` (`PredictedSimulationSystemGroup`, `.WithAll<Simulate>()`, deterministic — `SystemAPI.Time.DeltaTime` only); `PlayerInputGatherSystem` (client, `GhostInputSystemGroup`); `GoInGameClientSystem` (client) / `GoInGameServerSystem` (server — spawns the owner-predicted ghost, stamps `GhostOwner`, `LinkedEntityGroup` auto-despawn).
- **Netcode shape:** player = **owner-predicted** ghost; client sends input only; server is authoritative. Status: **code-complete + EditMode-verified**; live runtime blocked by [[DR-002_Unity66_Alpha_Netcode_Transport]].

## Conventions

DOTS/ECS conventions live in repo `CLAUDE.md` and the `dots-dev` skill's `dots-conventions.md`. Don't duplicate volatile API details here — link to context7-derived notes instead.