# Requirements — Level Design Canonical
## Gameplay Requirements
- [ ] **REQ-01 Tutorial exception**: Level 1 may have multiple solutions.
- [ ] **REQ-02 Optimal-tie rule**: Non-tutorial levels may have tied optimal solutions, but shortest optimal length must match `par`.
- [ ] **REQ-03 Par correctness**: `par` equals solver-confirmed optimal move count.
- [ ] **REQ-04 Over-par fail state**: Exceeding `par` causes drowning (`WASTED`) and level failure.
- [ ] **REQ-05 Decision quality**: Most stopping points present 2-3 plausible-looking options.
- [ ] **REQ-06 Punishment model**: Wrong routes resolve to death, dead-end, or forced over-par failure.
- [ ] **REQ-07 Variety**: Adjacent levels must not share dominant path feel or goal archetype.
- [ ] **REQ-08 Goal archetype rotation**: Campaign uses center, edge, alcove, and protected corner-adjacent goals.
- [ ] **REQ-09 Mechanic progression**: Introduce mechanics clearly, then combine for higher complexity.
- [ ] **REQ-10 Quadrant traversal**: Non-tutorial levels should traverse multiple quadrants (prefer four).
- [ ] **REQ-11 Tutorial timing**: Show a tutorial the first time a mechanic appears in the campaign.
- [ ] **REQ-12 Warp semantics**: Warps teleport to the paired tile and end movement (no continued slide).
## Verification Requirements
- [ ] **VER-01 Solvability**: All levels pass solver solvability.
- [ ] **VER-02 Optimal shortest correctness**: Solver + path checks confirm shortest optimal length equals `par` (ties allowed).
- [ ] **VER-03 Par lock**: Automated checks validate `par == optimal` for every level.
- [ ] **VER-04 Over-par death**: Automated gameplay checks validate drowning on move `par + 1`.
- [ ] **VER-05 Anti-repetition checks**: Adjacent-level variety checks are enforced.
- [ ] **VER-06 Warp behavior parity**: Solver and gameplay use the same warp-stop rule.
## Documentation Requirements
- [ ] **DOC-01 Canonical consistency**: High-level docs contain no conflicting rule sets.
- [ ] **DOC-02 Legacy labeling**: Older versioned docs are clearly marked historical/superseded.
- [ ] **DOC-03 Level intent clarity**: Active level docs explain trick, punishment model, and uniqueness.
## Out of Scope
- Rendering/art direction changes.
- New mechanic invention outside existing system.
- Economy/progression balancing unrelated to level quality.
