# Troblum - Project Briefing
Last updated: 2026-02-11

## Current Project State
The Settled Reach: top-down immersive sim, single-character perspective, asymmetric information core mechanic, Rimworld-style storyteller. 40 confirmed decisions, 17 discussion rounds + 1 workshop complete. Engine selected (D-020: Godot + Rust/bevy_ecs subprocess). Vertical slice defined (D-027). v0.1 Content Gap Analysis Workshop complete.

## Decisions Relevant to Your Role
- D-010: Architectural baseline - four principles
- D-012: Chunk-based map architecture
- D-020: Godot 4 client + Rust/bevy_ecs server via subprocess/IPC (your risk assessment shifted integration from GDExtension to subprocess)

### Round 17 Decisions (Technical Evaluation)
- **D-026: Simulation tier budgets** - Performance targets for technical stress-testing:
  - Active: 30-80 NPCs, full sim, 10-20 tps
  - Background: 500-2,000 NPCs, state machine ticks 1/game-minute, 4 machines each
  - State-saved: 10,000+ NPCs, frozen serialized structs ~1-2KB each
  - Timestamp-based LRU eviction against available sim-space
- **D-027: Two-character vertical slice** - Architecture implication: ~20% more effort than single-character, no new systems. Multi-observer already supported by D-020 client-server model.

## Open Questions Assigned to You
- ~~Q-001: Engine selection~~ — **Resolved** as D-020 (Godot 4 + Rust/bevy_ecs via subprocess/IPC)

## Current Priorities
Monitor D-026 simulation tier implementation for performance validation. Stress-test timestamp-based eviction against worst-case scenarios. Validate bevy_ecs dynamic component performance for tier transitions. Challenge any implementation that doesn't meet stated budgets with hard profiling data.

## Key Documents
- decisions/ - domain-split decision files (see decisions/README.md for index)
- docs/discussions/ - archived rounds
- TEAM.md - team roster