Troika!

TROIKA! is a science-fantasy role-playing game where you and your cosmopolitan group of fellow travelers explore the ends of the multiverse. You will fly on mystic barges, help dying gods, solve confounding crimes, plunder dead worlds, and meet strange & wonderful people. ​​

With just one book and a couple of six-sided dice, you'll be able to provide years of adventure for you and your friends.

You can find a plain text version of the TROIKA! rules here.