The Deepening is a ritual that can only be built by the Illians. It is the third of the Illian winter rituals; it is available at Priesthood. When it is completed, the entire world will be cooled down - changing some of the deserts to plains, some of the plains and grassland to tundra, and some of the tundra to snow tiles. Additionally, it spawns a random amount of Blizzards on the map. The Deepening has a construction cost of 600 Image:Production.gif.