In Evil High Priest, you're not playing to make friends, but to become the chosen High Priest of a Lovecraftian Great Old One! Each player takes on the role of a priest vying to prove they are the most devout (and, of course, most victorious) when the ancient entity finally awakens. Competition is fierce, as everyone worships the same dark deity, but only one can be the ultimate favorite.

The game employs worker placement mechanics, where you send your cultists to various locations across multiple boards to gather resources, summon horrific monsters, shatter the Elder Signs imprisoning your god, and even launch raids against the investigators who threaten everyone. Each action phase concludes when all cultists are placed, and then they return for a new cycle of worship and sabotage.

Components include cards, tokens, and several boards: your personal inner sanctum, the town board, the ritual board for spells, and the crucial cult board, representing the Great Old One you seek to unleash. And here's a neat twist: the cult board can be swapped between games, offering distinct experiences and tactics, such as the Cthulhu and Black Goat cults. Balancing the need to grow your sect and gather resources against the urgency of breaking Elder Signs and defending against investigators is the key to victory. Final scoring occurs when the last Elder Sign is shattered, revealing who truly pleased the cosmic horrors.