Forcefield (CTP1)

Forcefield is a city improvement in Civilization: Call to Power.
==Effect==
The Forcefield protects cities from military attack with a shimmering field of nearly impenetrable strength. Defenders within the city are virtually infallible, as their defense is increased by 12.
== Great Library entry ==
With the colonization of space, guided meteor guns, and orbital settlements, Earth populations faced increasing risk of death from the skies until the advent of the Forcefield. When the Forcefield detected high mass or energy, its floating carbon-60 buckyballs solidified, linking carbon to carbon in a solid dome as hard as diamond and a thousand times more resilient. Though certainly not invulnerable, the Forcefield reduced the terrorism of space against land.