Lycanthropes were beings afflicted by Lycanthropy, a powerful Curse that caused Mortalkind and some Giant-kin to change form into Beasts or hybrid humanoid-beast states. In their transformed shapes they were marked by heightened savagery and a strong physical response to the phases of the moon. Lycanthropy granted them an unnatural resilience to most forms of harm, which could be reliably overcome only by silvered weapons, potent magic, or certain gemstones known to disrupt the curse.
Two broad forms of lycanthropy were recognized. True, or natural, lycanthropy was inherited at birth and passed through bloodlines, though not all offspring of a lycanthrope manifested the condition. Pathologic lycanthropy spread as a curse, transmitted through open wounds exposed to the blood, saliva, or other secretions of an infected creature. Those who did not inherit full lycanthropy but were born of such lineage sometimes developed partial traits or a resistance to the curse. These individuals were known as Wereborn.
Afflicted lycanthropes experienced a loss of self during transformation, their personalities overtaken by a predatory mindset shaped by the nature of their strain. While transformed, they retained the memories of their humanoid lives, but their behavior was driven by hunger, aggression, and instinct. Upon returning to their original form, most remembered little of their actions, recalling them only as fragmented and dreamlike impressions, if at all. True lycanthropes differed in this regard, retaining their personalities across all forms and recalling their actions with clarity, which often made them more deliberate and dangerous than those newly cursed.