From publisher blurb: The Ice Age is Coming! Bring the Ice Age to your campaign with this setting set in a prehistoric world where humanity's future hangs by a thread. This setting offers three modes of play (Brutal, Gritty, and Fantasy) that changes what classes, species, and spells are available. In a Brutal campaign, play as a caveman (trog) or one of the humans (tlavatli) as glaciers drive a great migration from colder to warmer climes with no resources but your wits, your tribe, and your spear. In a Gritty campaign, ride with the wolves as a primal halfling or dig out from the hills as a primal dwarf, where only druids and rangers wield magic. Or play in a Fantasy campaign where dinosaurs, Greek myths and Lovecraftian horrors mingle in the forbidden lands of Hyperborea, Lemuria, and Atlantis. This campaign supplement includes seven sets of terrain along with encounter tables by campaign mode; 30 different terrain, travel, and weather hazards; eight new species; a new core class, the hunter, for Brutal campaigns; four new subclasses; new primal arms, armor, and equipment; rules for using skills in a cold environment; nine Atlantean deities; 38 new cold-themed spells; and 47 monsters grouped by their modern equivalents and prehistoric beasts (for Brutal and Gritty campaigns), and fantasy cold creatures (for Fantasy campaigns) with challenge ratings ranging from 0 (the humble penguin) to 13 (the terrifying shatter kraken). So grab your spear and gather your tribe. Will you make history ... or go extinct?