At BlizzCon 2023, Blizzard Entertainment announced a tabletop roleplaying game and a boardgame based on the Diablo series of video games. The TTRPG is slated for a 2024 crowdfunding campaign, and are being worked on in conjunction with the baordgame company Glass Cannon Unplugged and Genuine Entertainment, while the boardgame is set for fall 2025.
The TTRPG will share components and accessories with the boardgame. The system is an original system, and will use mechanics inspired by Diablo IV. It will explore the Sanctuary, with adventures in the overworld and underworld.
You can sign up for notifications over at Glass Cannon Unplugged.
This isn't the first Diablo TTRPG--back in 2000, WotC released the Dungeons & Dragons Adventure Game: Diablo II Edition for D&D 3E, written by Jeff Grubb and Bill Slavicsek. There were additional supplements, such as 2001's Diablo II: To Hell and Back (a dungeon crawl), and Diablerie (a world book).