# BRIEFING — 2026-10-02T02:47:00Z

## Mission
Implement Milestone 2: Party Engine & Scaling System for FreeExile with strict genuine logic, full test coverage, and adherence to GEMINI.md standards.

## 🔒 My Identity
- Archetype: teamwork_preview_worker
- Roles: implementer, qa, specialist
- Working directory: c:\Projects\FreeExile\.agents\teamwork\worker_m2
- Original parent: 914399d4-059b-422e-a9e6-44e1005de38a
- Milestone: Milestone 2: Party Engine & Scaling System

## 🔒 Key Constraints
- DO NOT CHEAT: Genuine implementations only, no dummy facades, no hardcoded test outputs.
- Exclusive write ownership:
  - `server/party/party_types.py`
  - `server/party/party_scaling_calculator.py`
  - `server/party/party_service.py`
  - `server/inventory/loot_filter_types.py`
  - `server/inventory/loot_drop_service.py`
  - `server/combat/monster_scaling.py`
  - `server/world/game_design_matrix_service.py`
  - `tests/unit/test_party_scaling.py`
- Code standards: <= 350 lines (hard cap 500), Python 3.11+ strict typing, @dataclass(slots=True, frozen=True).
- Verification passes: unit tests, e2e social party tests, doc/code hygiene check.

## Current Parent
- Conversation ID: 914399d4-059b-422e-a9e6-44e1005de38a
- Updated: 2026-10-02T02:56:00Z

## Task Summary
- **What to build**: Full party lifecycle engine (max 6 players, invites, leader promotion/disconnect, loot modes: PERMANENT, SHORT, FREE_FOR_ALL), party scaling calculator (nearby proximity detection, party EXP sharing with level gap penalty, loot multipliers, monster HP/armor/res/poise scaling), integration with GroundLootDrop / LootDropService, and GameDesignMatrixService.
- **Success criteria**: All tests pass (`pytest tests/unit/test_party_scaling.py`, `pytest tests/e2e_social_party/`), hygiene audit clean, genuine logic.
- **Interface contracts**: PROJECT.md, TEST_READY.md, existing e2e tests.
- **Code layout**: `server/party/`, `server/inventory/`, `server/combat/`, `server/world/`, `tests/unit/`.

## Key Decisions Made
- Implemented `server/party/party_types.py` with immutable `PartyMemberState`, `PartyState`, `LootAllocationMode`, `PartyRole`.
- Implemented `server/party/party_scaling_calculator.py` supporting both standard parameter signatures and optional monster level gap decay.
- Implemented `server/party/party_service.py` with `threading.RLock()` guarding all 6-player lifecycle actions.
- Extended `GroundLootDrop` with allocation fields and `can_player_pickup` method; integrated round-robin allocation in `LootDropService.generate_monster_drops`.
- Extended `MonsterScalingEngine` with party defense calculations for common, magic, rare, and boss ranks.
- Added `verify_matrix_integrity` alias and currency/rarity checks to `GameDesignMatrixService`.
- Added comprehensive unit tests in `tests/unit/test_party_scaling.py`.

## Artifact Index
- `.agents/teamwork/worker_m2/DISPATCH.md` — Assignment instructions
- `.agents/teamwork/worker_m2/BRIEFING.md` — Agent state and memory
- `.agents/teamwork/worker_m2/progress.md` — Liveness and progress tracker
- `.agents/teamwork/worker_m2/handoff.md` — Handoff report

## Change Tracker
- **Files modified**:
  - `server/party/__init__.py`: Export party types
  - `server/party/party_types.py`: Enums, DTOs, and PartyState
  - `server/party/party_scaling_calculator.py`: Mathematical scaling calculations
  - `server/party/party_service.py`: 6-player lifecycle and concurrency
  - `server/inventory/loot_filter_types.py`: GroundLootDrop allocation fields & can_player_pickup
  - `server/inventory/loot_drop_service.py`: generate_monster_drops party allocation & pickup check
  - `server/combat/monster_scaling.py`: create_monster_defense party scaling
  - `server/world/game_design_matrix_service.py`: verify_matrix_integrity alias & monotonicity checks
  - `tests/unit/test_party_scaling.py`: 17 comprehensive unit tests
- **Build status**: 123 passed (17 unit + 106 e2e)
- **Pending issues**: None

## Quality Status
- **Build/test result**: PASS (123/123 tests passing)
- **Lint status**: PASS (0 Hard Cap violations in check_code_and_doc_hygiene.py)
- **Tests added/modified**: `tests/unit/test_party_scaling.py` (17 tests covering party lifecycle, scaling math, loot allocation, and monster defenses)