Building placement

The player picks a structure type, position, and usually rotation. The game tests the footprint against occupancy, terrain slope, required neighbors (road access, a water tile, an ore patch), and cost. A valid placement writes the structure into the occupancy grid or spatial index and deducts cost; demolition reverses it, often with a partial refund. Tile grids (SimCity, Factorio, RimWorld) make footprints exact; gridless placement (Manor Lords, Foundation) allows arbitrary angles and curved streets. A ghost preview tinted valid or invalid is the standard interface. The occupancy map is the input to pathing, coverage, adjacency, and room detection.

A spatial puzzle with immediate feedback. Players plan space, fit footprints together, and live with early decisions as the layout fills. Gridless placement adds expressive freedom but also the chore of aligning things by eye.

• grid, offset grid, or gridless placement, with or without snapping
• footprint sizes and shapes, and whether rotation changes them
• terrain rules: slope tolerance, water, and foundations
• requirement rules such as road adjacency or resource tiles
• demolition refund and rebuild cost, which set how much commitment a placement carries

• Gridless placement leaves slivers and gaps that waste space and look untidy.
• Free demolition and full refunds remove commitment, so placement stops being a decision.
• A red ghost with no reason given makes hidden placement rules feel arbitrary.
• Permissive rules with abundant space make layout trivial.

• Early placements constrain later ones, producing path-dependent layouts and eventual rebuilds.
• Space becomes a resource that players trade against throughput or beauty.
• Players converge on standard modules, which leads to blueprint copying and sharing.

• Can natural-language or sketch placement ("put a market near the docks") keep the puzzle while removing the click cost?
• Which footprint rules make gridless placement as plannable as a grid?