Metal grids are underground networks of iron buried under most - if not all - cities.
Almost everything in cities requires magnetism to work. A vast metal grid allows these magnetic machines to work anywhere and everywhere within the city limits.
- Hovercars use the grid as a source of metal for their magnets to push against and thus, hover.
- Hover tanks are similar to hovercars, but are designed to be weapons of war.
- Hoverboards use the grid in the same way hovercars do. Most hoverboards are equipped with warnings in case the rider strays too far into the edges of the grid's boundaries.
- Hover struts are used in archictecture to enable hovering buildings. Without the vast grid as a source of metal, these structures would collapse.
- Bungee jackets are vests covered in straps and magnets. Intended to be used in case of a fire, bungee jackets "catch" a person as they jump off of a burning building and use the magnets to absorb the wearer's momentum until the person stops falling. The grid allows a person to hoverbounce quite a ways away until their momentum is spent, if need be.
- Crash bracelets are used along with hoverboards and are designed to stop a person from falling. However, unlike a bungee jacket -which distributes the force of slowing a fall to a standstill across the whole torso- crash bracelets concentrate all that force on the wrists. Without a source of metal to push against, such as the grid, crash bracelets wouldn't work.