When a lich is destroyed, its phylactery (which is generally hidden by the lich in a safe place far from where it chooses to dwell) immediately begins to rebuild the undead spellcaster's body nearby. This process takes 1d10 days-if the body is destroyed before that time passes, the phylactery merely starts the process anew. After this time passes, the lich wakens fully healed (albeit without any gear it left behind on its old body), usually with a burning need for revenge against those who previously destroyed it.