Every two to four centuries the powers of the Old Gods rise like a hungry tide, and their cults go into a frenzy of activity. Scholars are still uncertain what triggers a Churning, despite nearly three millennia of tracking their occurrences, but the effects of them are well-documented:
- Cultists worshipping the Old Gods are empowered, able to use magics more powerful than their level of training would normally allow for, and those with a more martial bent can take the Old Gods’ corruption into themselves to become more physically capable and dangerous in combat
- The demonic servants of the Old Gods are able to enter the mortal world with notably more ease, and can influence events using less effort than they would normally need to expend. This effect does not extend to the celestial servants of the True Gods, unfortunately, which often results in mortals facing the eldritch monsters who serve the Old Gods without any divine allies at their side.
- Cultists of the Old Gods seem to pop up out of nowhere, in far greater numbers than the population of an area would be able to support before a Churning began without falling into chaos. Given that some captured cultists in previous Churnings seem to have no memory of where they came from or of the surrounding area, it’s thought that they are either being conjured by the Old Gods out of nothing or are being stolen from some other realm and used as troops in the material plane. While some express sympathy for these poor deluded souls, they are all devout followers of the Old Gods and all attempts to reason with them or return them to their senses have resulted in either immediate violence or an inevitable betrayal.
- Finally, magical Gates appear in areas where leylines converge, portals to the peculiar and incredibly powerful demiplanar crossroads known as Veilguard, which has been a critical tool in the arsenal of the nations of the Continent to deal with the chaos that the Old Gods unleash during a Churning.