Rust Legion ECS Gameplay

Use this skill to build ECS gameplay code in Rust, especially in projects using Legion or a Legion-like architecture. Keep components as data, systems as focused logic, and resources as shared singleton state.

Core Workflow

1. Identify entities, components, systems, and resources from the feature.
2. Add data-only components before adding systems that consume them.
3. Put entity construction in spawner functions or factories.
4. Use queries that request only the components a system needs.
5. Sequence systems with schedules and flush points when later systems must observe structural changes.
6. Verify behavior through one small gameplay path before adding more entity types.

Read Next

Read references/ecs-gameplay-patterns.md for component design, system ordering, spawners, rendering systems, and ECS review checks.

Source Notes

Guidance is transformed and paraphrased from Hands-On Rust Chapter 6 and the official companion source repository. Current crate context was checked against Legion and Bevy ECS docs. If the target project uses Bevy, hecs, specs, or another ECS, adapt the architecture instead of forcing Legion APIs.