Grid System Architecture

Status: RESOLVED — July 19, 2026

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Coordinate System

Grid Dimensions

• 8 columns (x) × 12 rows (y) — portrait orientation
• Height layers (z): −1 (pit), 0 (ground), +1 (platform), +2 (elevated), +3 (tower/peak)

Data Model

• 2D array Tile[8][12] with height as a tile property.
• One unit per (x, y) coordinate — no stacking at different heights on the same tile.
• Height determines advantage, not occupancy.

Grid
├── Tile[x][y]
│   ├── height: int (-1..+3)
│   ├── terrainType: enum (Grass, Water, Lava, Void, etc.)
│   ├── occupant: Unit | null
│   ├── hazard: HazardData | null
│   ├── cover: CoverData | null
│   └── preparedEffect: RitualData | null
├── Units[]: List<Unit>
└── activeEffects[]: List<GridEffect>

Rendering

• Custom mesh grid — not Unity Tilemap. Full control over height extrusion and isometric projection.
• Height projection: shadow offset on ground plane for depth readability.
• Z-ordering: paint back to front, bottom to top, then height ascending.
• Characters: 2D sprites on billboarded quads in 3D space.

Pathfinding

• A with height cost* — climbing +1 height costs +1 movement. Descending is free (may trigger fall damage).
• Movement abilities (Flight, Shadowstep) bypass height cost via ability flags, not pathfinding modifications.

Line of Sight

• Bresenham raycasting on grid data (not Unity physics). Deterministic, fast, testable.
• Cover tiles block LOS if between attacker and target at same or higher height.
• Height advantage +3: ignores LOS blockers at or below attacker height.

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Height Mechanics

Height Difference	Range Mod	Damage Mod	LOS Rule
+3 or higher	+2	+30%	Ignores LOS blockers ≤ attacker height
+2	+1	+20%	Normal LOS
+1	+1	+10%	Normal LOS
0	0	0%	Normal LOS
−1	−1	−10%	Normal LOS
−2 or lower	−1	−20%	Normal LOS

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Open Questions

• [x] Isometric camera angle: 30° or 45°? 45°. Standard isometric. Better depth visibility for 2.5D hybrid.
• [ ] Grid mesh generation: runtime (allowing dynamic terrain changes) or pre-baked per map?
• [ ] Height visualization: color-coded ledges, shadow projection, or both?