Call of Cthulhu Mansion of Madness: Behind Closed Doors Campaign Guide

Quick answer

Run the five-scenario Mansions of Madness Vol. 1 campaign by pacing reveals, tracking sanity, and linking clues across standalone adventures for a cohesive mini-campaign.

How to run the Behind Closed Doors campaign

1. 1. Establish the overarching mystery: Before session one, decide the central threat (e.g., a cult, an artifact, a location) that ties all five scenarios together. Write a one-sentence hook that explains why each scenario matters to the main plot. Common mistake: starting with no connection leads to a disjointed campaign. The hook can be vague initially and clarified later.
2. 2. Order the scenarios for narrative flow: Read all five scenarios and arrange them in a sequence that builds tension. Place the most straightforward scenario first and the most lethal last. The book allows any order, but a rising difficulty curve keeps players engaged. Checkpoint: after session two, ask players if the clues feel connected. If not, adjust the order or add a linking scene.
3. 3. Plant recurring clues and NPCs: In each scenario, drop at least one clue (a document, a witness, an item) that references an event or person from a future scenario. Reuse one or two NPCs across scenarios to create continuity. Common mistake: overloading players with too many clues. Limit to one major and one minor clue per scenario.
4. 4. Track investigator sanity and corruption: Use the sanity rules from the Keeper Rulebook. Keep a visible sanity tracker for each investigator. When a scenario ends, apply a cumulative sanity penalty for the horrors witnessed so far. Checkpoint: if any investigator reaches zero sanity before the final scenario, offer a temporary recovery scene rather than removing them from the campaign.
5. 5. End each scenario with a cliffhanger: Close each session with a brief scene that hints at the next scenario's location or threat. This can be a vision, a phone call, or a newspaper headline. Keep it under two minutes. Common mistake: skipping the cliffhanger because the session ran long. Even a single sentence maintains momentum.
6. 6. Prepare a finale that references earlier choices: In the final scenario, include callbacks to decisions investigators made in earlier scenarios. If they spared an NPC, that NPC returns as an ally or enemy. If they destroyed an artifact, the final threat is weaker. Checkpoint: note player choices during each session. A simple spreadsheet with three columns (choice, scenario, consequence) helps you reference them naturally.

Product facts

• Call of Cthulhu Mansion of Madness: Vol. 1 Behind Closed Doors: Mansions of Madness Vol. 1 contains five scenarios for use with the Call of Cthulhu Starter Set or the 7th Edition Call of Cthulhu: Keeper Rulebook. You need the Starter Set or Keeper Rulebook to run these scenarios; this book is an adventure supplement, not a standalone rulebook.