Cthulhu Dark: House Rules
Here are my house rules for Graham Walmsley's Cthulhu Dark, which provides a rules-lite alternative to Call of Cthulhu while distilling the essence of cosmic horror roleplaying. These rules are meant for more 'realistic' roleplaying where investigators become unmoored from human society rather than simply 'going insane'. Delta Green was a big inspiration here.
Anchors & Insanity
- At character creation, each player creates an Anchor. This is an NPC from the Investigator's mundane life (outside the scope of the character's adventures) who is important to the Investigator's identity and tethers them to humanity. A spouse. A pet. A sibling. A child. A coworker. A good friend. Et cetera.
- When an Investigator's Insight reaches 6, they are changed permanently, and must strike out their Anchor. The player is given the spotlight as they describe--or roleplay--the permanent change in their Investigator's personality as they become unmoored from mundane reality. Then, the camera cuts to the Investigator's Anchor NPC, and the player describes a brief scene of the Anchor losing touch with (or deliberately turning away from) their relationship with the Investigator.
- After reaching Insight 6 and striking out an Anchor, the player can continue to play their Investigator, roleplaying their damaged and/or deranged new personality. Such an Investigator may not survive for very long.
- When an Investigator's Insight reaches 6, it becomes locked; the Investigator cannot roll the Insight die anymore, and therefore cannot repeat rolls for better results.
- For a campaign or scenario of more than one session, each Investigator creates several Anchors (more Anchors for longer games). At the start of each new session, all Investigators unlock their Insight score and reset it to 1, while keeping the personality/worldview changes instilled by previous experiences.
Harnessing the Occult
- If an Investigator finds the means to learn an occult ritual or magic spell, they may absorb the knowledge by increasing Insight by 1 (no roll).
- Once an Investigator learns how to perform occult magic, they may do so by rolling the Insight die, without the benefit of the Human or Occupation die. It is dangerous to harness the occult, and barely succeeding can have worse consequences than failure!
- If an Investigator's Insight is locked at 6, they roll the Failure die instead of the Insight die when performing occult magic. The occult action itself always succeeds, but the Failure die result determines the severity of its inevitable side-effects. For some rituals, a roll of 6 could mean the death of the Investigator. For others, a roll of 6 could mean the end of the world!