Class X planets are the result of a failed Class U planet in a star system's Hot Zone. Instead of becoming a gas giant or red dwarf star, a Class X planet was stripped of its hydrogen/helium atmosphere. The result is a small, barren world similar to a Class B planet, but with no atmosphere and an extremely dense, metal-rich core.
- Extreme attrition damage to units outside Pressure Domed Cities.
- No Water for Naval Units
- No Water for Fishery or Waterport
- No Atmosphere for Air Units or Airport
- All facilities require Pressure Dome (w/ Heat Shield) Upgrade or suffer damage.
- Mine produce X3 Metal.