Cohors Cthulhu RPG Gamesmaster's Guide - EN

Control the Course of the Hidden Wars
Take your place as a gamemaster of a dark epic RPG set in an age of world-shaking heroes and villains vying to protect or corrupt humanity. This is a setting rife with brutal battles, sinister plots, and murderous intrigue, blending Lovecraftian cosmic horror with ancient civilizations who must rise above old feuds.
As gamemaster you will bring this world to life, shining a light into dark corners along the borders of an expanding empire encroaching on proud cultures already beset by nefarious threats. 
The supernatural wars are instigated and controlled by secretive cabals. The most powerful of these are led by quasi-immortal beings who have turned to dark magic, poorly understood relics, and unholy pacts to extend their lifespans. This includes the last remnants of fallen Atlantis, whose shadow spreads wide. Some of these groups are largely benevolent, if pragmatic and sometimes cruel, seeking to safeguard humanity against its greatest foes. Others are fully devoted to the Outer Gods and would see the world burn.
Will your players rise to become great legends or, like so many others, fall to the corruptive temptations offered by Mythos gods? Their fates are in your hands.