Evil yuan-ti conspire to destroy a kingdom using dark rituals and the bones of a long-dead king. To win the day, heroes must storm the yuan-ti fortress and wrest the bones from the cultists' clutches before they complete their rituals and unleash a far greater menace upon the world. DD3 Fortress of the Yuan-ti is a Dungeons & Dragons adventure designed for 6th level characters. The third adventure in a three-part series, it can also be played as a standalone adventure. ARI MARMELL has contributed to scores of RPG and fiction products. His recent work for Wizards of the Coast includes the Complete Mage and Complete Champion supplements as well as The Sinister Spire adventure.