Radiation Hardiness is a Cravers-specific technology on the Diplomacy and Trading technology tree with a research cost of 130 . It unlocks an Empire Improvement, requires research in Xenology or in Soil Xenobiology, and allows no further research.
"Developed by Craver biologists, certain treatments applied to developing Craver eggs can result in pupae that are highly resistant to radiation."
- -25% Upkeep on Ships
"These advanced complexes produce workers that are highly radiation-resistant. As a result, they can be worked harder and longer before they die in the highly irradiated atmosphere of space, which in turn reduces ship maintenance costs."