The Betrayer's Fog

The Betrayer's Fog, most often just called the Fog, is a phenomenon that happens exclusively on Siarvald.   Every so often, a dense fog falls over the entirety of the continent. This event has been observed to somehow cover the entirety of the continent at the same time and to disappear just as quickly as it comes. Some scholars believe that increased aggression amongst both animals and monsters is a sign that the fog will soon fall. When it does, it usually lasts for about a day.   While this fog may seem benign at first, it is considered an ill portent by the Siarvaldan. King Vah'dis decreed, at the very beginning of his reign, that all inhabitants of the continent were to interrupt their daily lives to go back home and barricade themselves whenever the Fog rises. This is because monsters grow increasingly aggressive during that time, even going so far as to boldly attack humanoid encampments and any wandering adventurers. To make matters worse, it has been found that monsters attacking during this time are somehow imbued with strange, poison-related powers, such as venomous claws sprouting where they previously had none or the ability to breathe poison. Those effects are thought to be the influence of the Betrayer himself, hence the name, and disappear the moment the Fog lifts.