This is The Spectre King (1992), a book of scenarios for the Pendragon RPG. Spirits of vengeful knights returned from the grave are a bit of an ongoing thing in King Arthur, and the titular adventure is a great example, with a fantastic connection to in-game history.

Pendragon is game about generations. When you create your first character, you roll up what their father and grandfather got up to during their lives during the Saxon invasions and incursions. Chances are, at least one player’s father was present at the Battle of Maisbeli, where the Duke of Gloucester captured then executed the reaving Saxon King Hengist in humiliating fashion. That initial character’s son might then take part in this adventure, when Hengist returns to have his bloody vengeance. I love how all that history and happenstance can potentially come to bear. Its a pretty great mystery scenario, to boot.

Two more great ones here. One about an unusual werewolf that subverts a lot of fantasy RPG trope is particularly fun. Another about another spectral knight is a wild, multi-year affair involving a dragon and a curse and some excellent twists. Both spring surprisingly out of mundane events players might participate in, which I like.

There’s also details on Arthur’s annual grand tournament, with details on events that transpire every year, info on Cambridge and a couple other scenarios that didn’t quite grab me. The unfortunately named Stephen King did the cover art, which I quite like, but damned if I can find anything else about the artist. Of the interior artists, Arnie Swekel is of particular note. He did some work for D&D in the mid-to-late 90s and I quite enjoy his more dialed back stuff here.