# BRIEFING — 2026-10-01T03:15:00Z

## Mission
Formulate exact drop-in code fixes for `server/world/combat_engine.py` regarding corpse multi-hit overkill and evasion timestamp default.

## 🔒 My Identity
- Archetype: explorer
- Roles: teamwork_preview_explorer
- Working directory: c:\Projects\FreeExile\.agents\teamwork\explorer_m2_progression_2_gen2
- Original parent: 6f4a2aa2-4315-4660-8cb7-8352a7220c95
- Milestone: M2 Iteration 2

## 🔒 Key Constraints
- Read-only investigation — do NOT implement / modify source code directly
- Propose exact drop-in code fixes for subsequent implementer
- Keep file size strictly <= 350 lines (soft cap), <= 500 lines (hard cap), functions <= 50 lines
- Strict typing, zero lip-service, verifiable evidence chain

## Current Parent
- Conversation ID: 6f4a2aa2-4315-4660-8cb7-8352a7220c95
- Updated: 2026-10-01T03:15:00Z

## Investigation State
- **Explored paths**:
  - `server/world/combat_engine.py`
  - `server/world/level_progression_service.py`
  - `tests/unit/test_level_progression_service.py`
  - `tests/e2e/test_poe2_zone_and_encounter_e2e.py`
  - `tests/e2e/test_level_progression_e2e.py`
  - `c:\Projects\FreeExile\.agents\teamwork\challenger_m2_progression_2\challenge_combat_progression.py`
  - `c:\Projects\FreeExile\.agents\teamwork\reviewer_m2_progression_2\handoff.md`
- **Key findings**:
  - Corpse multi-hit in `calculate_damage` re-evaluates `is_fatal = (defender.current_hp <= 0.0)` which is True when HP is already 0.0. Fixed by tracking `was_alive = (defender.current_hp > 0.0)` and `is_fatal = was_alive and (new_hp <= 0.0)`.
  - Phantom evasion at start caused by `CombatActor.last_evasion_timestamp_ms` defaulting to 0. Fixed by defaulting to `-1000` and guarding `if defender.last_evasion_timestamp_ms >= 0:`.
  - Level 100 death listener silencing in `level_progression_service.py:298-299` fixed by removing the early return.
  - Empirically verified with local test harness `verify_drop_in_fixes.py` and challenger runner (all 6 challenge suites passed, exit code 0).
- **Unexplored areas**: None for M2 scope.

## Key Decisions Made
- Formulated exact drop-in diffs and line number specifications for `server/world/combat_engine.py`.
- Formulated companion fix for `server/world/level_progression_service.py` lines 298-299.
- Verified hygiene and type strictness (file size ~195 lines, functions <= 43 lines).

## Artifact Index
- DISPATCH.md — Dispatch log
- BRIEFING.md — Working memory
- progress.md — Liveness tracker
- report.md — Comprehensive drop-in code fix report
- handoff.md — 5-component handoff report
- verify_drop_in_fixes.py — Empirical mock test harness