From the introduction: An arcane prosthetic is a magic item designed to replace a limb. In most cases, these prosthetics are designed for adventurers who have lost limbs but still feel the pull of the questing life––though some just want to recover the dexterity and ease of their fully-abled lives. Others were born without limbs, and these items are akin to weapons or magic––not replacements but tools to interact with the world. Still a fourth (albeit rare) party of people sever their limbs in order to permanently replace them with magical prosthetics, believing that they are improvements on the natural form.