James Jacobs is an American designer and author of role-playing games and texts in the fantasy, horror and the occult genres. In the 2000s, he served as the editor-in-chief of Dungeon magazine, published by Paizo Publishing.
Jacobs has been involved in the roleplaying industry since the age of fourteen, when his adventure "Scepter of the Underworld" was published in Dungeon in 1988. Since then, he has authored and co-authored several other products for the Dungeons & Dragons role-playing game, including Dungeon Master's Guide II (3e) (2005), Lords of Madness (2005), and Red Hand of Doom (2006). He also wrote Fiendish Codex I: Hordes of the Abyss (2006) with fellow Paizo editor Erik Mona.
Jacobs oversaw Pathfinder, the Adventure Path-focused monthly publication from Paizo. He also wrote "Burnt Offerings", the adventure featured in Pathfinder's first issue.
Among Jacobs' other writings is the popular "Demonomicon of Iggwilv" feature in Dragon magazine, and he has contributed a number of adventure stories for Dungeon. Jacobs has also created many Dungeons & Dragons creatures, with the ulitharid, draknor, and the kaorti among the most prominent.