Procedural Generation Pipeline Architecture

Status: RESOLVED — July 19, 2026

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Approach

MVP: Editor-crafted maps using grammar rules. Runtime: load pre-generated maps.

The grammar engine runs at editor time, not runtime. A designer uses the grammar rules + rule configs to generate maps, tweak results, and export validated maps. Runtime loads the exported map files. No runtime generation for MVP.

This approach:

• Makes map editing possible (designer can hand-tune grammar output)
• Gives a more crafted experience at launch
• Keeps the grammar engine available for future procedural generation
• Eliminates runtime generation bugs and performance concerns

Future: Runtime Generation

The same grammar engine can be wired to runtime in v0.2+ when full procedural variety is needed. This is architecture-compatible — runtime just calls the same grammar pipeline with a seed instead of loading an exported file.

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Pipeline (Editor Time)

BIOME SELECT → TEMPLATE SELECT → GRAMMAR GENERATE → ENEMY PLACE → VALIDATE + POLISH → EXPORT

Editor Tool: Grammar Window

A custom Unity Editor window that exposes:

• Biome selector dropdown
• Template selector dropdown
• Grammar rule configs (sliders for density, toggle rules on/off)
• "Generate" button
• "Validate" button
• "Export to Runtime Asset" button
• Seed display (for reproducible generation)

Export Format

Maps are exported as JSON or ScriptableObject assets consumed by the runtime battle scene:

ExportedMap
├── biomeId: string
├── templateId: string
├── tiles[8][12]: TileData
│   ├── height, terrainType, hazard?, cover?
├── deployZones: PlayerDeployZone, EnemyDeployZone
├── enemyPlacements[]: EnemySpawnData
└── dynamicEvent?: DynamicEventConfig

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Grammar Engine

Approach

• Rule-based grammar — define rules like "every +3 tile must have a ramp within 2 tiles."
• Simpler than Wave Function Collapse, transparent, designer-tunable.
• Rules are configurable via ScriptableObjects (GrammarRuleConfig assets).

Rule Categories

Category	Example Rule
Height	hill_cluster(x, y, radius, maxHeight)
Cover	wall_line(start, end, hp)
Hazard	hazard_pool(center, radius, type)
Path	all_tiles_reachable_from(deployZone)

Validation

Same solvability checks from the design doc, but run in editor:

• No one-shot kills on turn 1
• At least 2 valid opening moves
• No surround traps
• Map connectivity
• Casters target valid tiles

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Maps for MVP

• 2 biomes × 4 templates = 8 editor-crafted map types
• ~3 variants each = 24 total exported maps
• • 2 hand-crafted boss arenas
• • 1 tutorial map
• Total: ~27 maps to author

Editor grammar tools should reduce per-map creation time from hours to minutes.

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Open Questions

• [ ] How many map variants per template? 3 each = 24 maps. Is this enough for launch replayability?
• [ ] Grammar rule config: ScriptableObject per biome, or unified config file?
• [ ] Export format: JSON (diffable) or ScriptableObject (faster loading)? Both?
• [ ] When does runtime generation ship? v0.2 with Island 3?