GHOST PREVIEW
A translucent hologram of a structure shown at the cursor before placement — green when valid, red when blocked — letting players see exactly what they're about to build and where.
- SOLO-DEV COST LOW
- TIMING REAL-TIME / TURN
- COMMON IN STRATEGY · AUTOMATION · BASE-BUILDING · CITY-BUILDER
It is the universal grammar of construction interfaces: StarCraft's building footprints, Factorio's entity ghosts (which evolved into plannable ghost-buildings that bots fulfill later), The Sims' furniture preview, and every survival builder since. Designers use ghost previews because construction is a commitment and the preview removes placement anxiety: rotation, footprint, snapping, and terrain conflicts all resolve visually before resources are spent, which is the difference between confident building and undo-button archaeology. The pattern also carries information density cheaply — range circles for turrets, connection lines for power, coverage overlays appear naturally on the ghost. Key decisions: how much validity detail the ghost communicates (binary red/green versus specific blockers highlighted), whether ghosts can be queued as construction orders (Factorio's ghost-planning turns preview into a programming layer), and how the preview handles partial validity like a wall segment crossing a rock. Pitfall: a lying ghost — any gap between what the preview showed and what placement actually produced (offset snapping, hidden clearance rules) destroys the trust the entire pattern exists to provide; the ghost must be pixel-honest.