Ravenloft is a realm always in dusk and shadow. Creatures stalk the deep forests and the castles are filled with horrors that keep the peasants held up shut tight in their homes. And it's into this realm that your party is going to be headed. Better get yourself a guide. Thankfully, Van Richten's Guide to Ravenloft is now available. It's just what you need.
From the announcement:
Van Richten's Guide to Ravenloft is out now and ready to aid you in your journey through the horrific Domains of Dread. 💀 Inject some fright into your fight with new backgrounds, trinkets, subclasses, Dark Gifts, creatures, and more!