Some ancient civilizations lived on this planet until they got too industrialized,ambitious.They tried to play God.They did science experiments to create new species and evolve them.But it backfired as these creatures were parasitic and quickly infected,consumed and assimilated their creators.(Think Halo/Resident Evil) Alarmed by the rate spread,the last group of survivors had to destroy every living species on the planet to stop them from spreading and hope that they would eventually die out,leaving behind a dead world. Some backstory,so these dead worlds would be full of ruins and prolonged exposure would kill you,(radiation/poison).However,the rewards would be great,lots of loot and resources.Alas,you can't just waltz in and take it all,there would be Dead Space like monsters that will pop out from underground\ruins and then proceed to feast on your entrails.
a dead planet full of unknown technologies, full of monsters that are nothing more than bad so many successful experiments such ruins ... I like good idea
Planet full of monstrous creatures,dangerous levels of radiation,old ruins,not to mention a lot of loot if we somehow survive everything on the planet that's trying to kill us(which,I take it,is basically everything)... Sounds like an awesome idea! Just hope the loot is good though,or I'll waste alot of resources for a trip to the Land-Of-Everything-That-Wants-You-Dead.
This kinda sounds like what the tentacle worlds would be like... And I guess these planets would have threat levels varying from maybe 70-100
