Hostile Sun RPG Playtest

Players learn about Alchemy and uncover explorers on the strange moon that is infested with Moon Mason Bees

Playtesting and Rules Updates

Under a Hostile Sun Playtests on Youtube

  • Under a Hostile Sun is being refined through playtesting.  If you want to see the playtesters in action, check out our YouTube channel.  
  • Much has been learned and much has been adjusted.  The link on the home page connects to the newest ruleset and of course any updates are also on
  • Some of the pages on this site might still reflect older rules.  These will be updated soon.  

Rules Errata 

  • Opportunity is now handled with a dice roll at the end of each round – the size of which changes depending on round number and the environments risk level.
  • Movement is now done with squares instead of hexes.   Characters have better movement rates than before.  
  • Alchemy and creature rules have been heavily revised and streamlined.
  • There are now six character Archetypes – the Aerospace Doctor, the Priest of the Immutable, the Roboticist, the Smuggler, the Beast Rider, the Hallowed Hunter and the Chemist.  
  • Pets consist of a Buff given to the tamer, stat pools that can be spent to allow the tamer to reroll a check with the corresponding stat, a Food Resource that is used to refresh that stat pools and a conversion to an elite currency the pet can perform if given the correct resources.  



  • All images in the rulebook are now made with Photoshop and licensed stock images or hand drawn images.