Span Builder is a physics construction puzzle. Each level is a gap between two cliffs with a few fixed anchor points. Drag between grid points to place beams: road beams form the deck the car drives on, wood is cheap and light, and steel is strong but expensive. Beams can span at most four grid squares and the whole bridge has to fit the level’s budget. When you are ready, press Test: gravity takes over, every beam shows its strain from green to red, and overloaded beams snap. Get the car to the far side to clear the level — the less you spend, the more stars you earn. Six levels, from a little creek to a canyon crossing under a heavy load. Your designs are saved on this device.
How to play Span Builder
Goal: Build a bridge within budget that carries the car to the far cliff.
Keyboard & mouse
- Drag from one grid point to another to place a beam; click a beam to remove it
- 1 road, 2 wood, 3 steel; T tests and E returns to editing
- Arrows move a cursor, Space starts and ends a beam
- P or Escape to pause
Phone & tablet
- Drag between grid points to place a beam; tap a beam to remove it
- Use the toolbar to choose material, clear, and Test or Edit
Rules
- Beams join at grid points; anchors on the cliffs are fixed and never move.
- The car only drives on road beams — make a continuous deck from cliff to cliff.
- Wood and steel beams support the deck from below or above; triangles are strongest.
- During a test, beams turn from green to red as strain builds, and snap if overloaded.
- Spend 75% of the budget or less for three stars, 90% or less for two.
Tips and strategy
- A single straight deck sags and snaps — add triangles under or over it.
- Use steel only where the strain turns red; wood is enough elsewhere.
- Short beams are stronger than long ones when carrying the same weight.
