Deepen your investigation with the best expansions for Arkham Horror 3rd Edition.
Arkham Horror 3rd Edition is already a rich cooperative experience, but its expansions are where the game truly stretches its wings. Each box adds new scenarios, investigators, and mechanics that evolve the base game rather than simply adding more of the same. This guide ranks them by overall quality, mechanical interest, and thematic payoff. All expansions are compatible with each other unless noted.
Expansion | 1-6 players
The most acclaimed expansion for Arkham Horror 3rd Edition. Dead of Night adds the Midnight Mask and Shattered Bonds scenarios, new investigators like Diana Stanley and Carolyn Fern, plus a haunting new set of mythos cards. It deepens the narrative and psychological horror of the base game without overwhelming new players.
Expansion | 1-6 players
A coastal campaign that sends investigators to Innsmouth and Kingsport. Under Dark Waves introduces two new scenarios with heavy maritime Lovecraftian dread, new Aquatic-trait monsters, and the Obsession mechanic that ties investigators' backstories to the mystery at hand. A standout for fans of the Innsmouth lore.
Expansion | 1-6 players
Secrets of the Order adds two new investigators and a cult-hunting scenario set in Arkham itself. The Silver Twilight Lodge mechanic lets investigators join or oppose the cult for strategic advantage at a narrative cost. Great for groups who want more decision-making tension built into the story.
Expansion | 1-6 players
Takes the investigation to South America with jungle exploration rules and a Serpent Cult to dismantle. Path of the Serpent features three linked scenarios, new Ancient One variants, and environmental hazard tokens that change how you move through the board. Best played after completing the base box.
Expansion | 1-6 players
Two new scenarios set aboard a train and ocean liner — moving environments that shift each round. Horrific Journeys is mechanically inventive with its transit board overlays and changing layouts mid-scenario. One of the most unique expansion experiences in the line.
Campaign Expansion | 1-6 players
A full campaign-style expansion with persistent consequences across five connected scenarios. The Innsmouth Conspiracy adds the returning Innsmouth Legacy track, where decisions carry forward between sessions. The closest Arkham Horror gets to a legacy-style campaign experience.
Start with Dead of Night — it's the most polished and universally loved. Innsmouth Conspiracy is essential if your group wants a campaign-style multi-session experience. Avoid buying all expansions at once; the base game alone takes 20+ plays to fully explore.