The first physical sign of ruidium corruption is a bright red rash that appears on the creature’s body where it made contact with the ruidium. This process, called ruidium corruption, starts with physical effects but can also cause psychological distress in cases that have progressed beyond the initial stages.

When used for too long, items that have been infused by ruidium spread their crystalline structure to the creatures that wield them. While ruidium might seem like an obvious blessing from the mysterious realm of the Netherdeep, ruidium items do not come without their downsides. Magical items can be infused with ruidium to become even more powerful, and even mundane items develop magical properties after sufficient exposure. It goes without saying that the scholarly factions investigating ruidium would have great use for a party of adventurers that are able to get a hold of ruidium items. The chances of spread are greatly increased when creatures or objects remain in prolonged contact with it. Ruidium’s properties are yet to be fully realized, but initial research of the mineral shows it can spread its crystalline structure into both organic and inorganic substances. Since its discovery, different scholarly factions have been at odds trying to secure a steady supply for research. Not much is known about ruidium beyond that it is powerfully magical. This mineral got its name from its similarities in color to the second Exandrian moon, Ruidus. Ruidium is described as a “slick, oily stone veined with blood-like streaks” that forms in crystalline structures that run through the sunken caverns of the Netherdeep. Players beware, spoilers for Call of the Netherdeep lie ahead! The full extent of ruidium’s role in Call of the Netherdeep is still under wraps, but let’s take a look at what we know about it and its double-edged potential.

While it isn’t guaranteed when the players will first encounter ruidium, one thing is for sure: its discovery will present their characters with unique challenges. This alien mineral imbues its twisted energy into things it touches. In the adventure Critical Role: Call of the Netherdeep, characters are bound to come across the otherworldly material known as ruidium. Monstrous Compendium Vol 3: Minecraft Creatures

The Wizard Tales Vol I-III by Red Tash