James Jacobs is an American designer and author of role-playing games and texts in the fantasy, horror and the occult genres.

Jacobs has been involved in the role-playing industry since the age of sixteen, when his adventure "Scepter of the Underworld" was published in Dungeon #12 in 1988.^[2][3] Jacobs grew up in Point Arena, California, and went to college at the University of California, Davis.^{[citation needed]}

He moved to Seattle after graduating from college and worked his way into Wizards of the Coast's sales department.^{[citation needed]} Jacobs has been the developer, lead designer, and sometimes cartographer on releases for Bastion Press, Green Ronin Publishing, Wizards of the Coast, and Paizo.^[3] Jacobs has authored and co-authored several other products for the Dungeons & Dragons fantasy roleplaying game, including Dungeon Master's Guide II, Lords of Madness, Frostburn, and Red Hand of Doom.^[4][5] He also wrote Fiendish Codex I: Hordes of the Abyss with fellow Paizo editor Erik Mona.^[5] Jacobs and Erik Mona co-wrote Expedition to the Ruins of Greyhawk (2007), a 3rd edition D&D remake of Greyhawk Ruins (1990).^[6]

Jacobs became the associate editor for Dungeon magazine, and later became the managing editor for the magazine.^[3] In the 2000s, Jacobs served as the editor-in-chief of Dungeon magazine, published by Paizo Publishing.^{[citation needed]} Jacobs described himself as "one of the chief architects" of the Dungeon Adventure Paths, in addition to doing some work on all of the other adventures published in the magazine.^[3] Jacobs became the Editor-in-Chief for Dungeon magazine in June 2006.^[7] Jacobs is the Creative Director for the Pathfinder Adventure Paths-focused monthly publication from Paizo.^[3] He also wrote "Burnt Offerings", the adventure featured in Pathfinder: Rise of the Runelords #1.

Among Jacobs' other writings is the "Demonomicon of Iggwilv" feature in Dragon magazine, and he has contributed a number of adventure stories for Dungeon. Jacobs has also created many notable Dungeons & Dragons creatures, with the ulitharid, draknor, and the kaorti among the most prominent.