Introduction
Call of Cthulhu 7e uses phobias and manias to give an investigator's horror a recurring shape. A phobia is an irrational fear or avoidance pattern. A mania is an obsession or compulsion that demands attention. The Keeper Rulebook includes 100-entry sample tables for both, rolled on 1D100, and it also lets the Keeper simply choose an appropriate result. The tables are a starting point. They cannot tell you what is interesting, appropriate, or respectful for a specific investigator.
Do not treat these labels as real-world diagnoses. They are genre-game devices describing the lingering effects of cosmic horror. At a thoughtful table, they create a choice, a clue, or a new relationship with the investigation. They do not exist to mock disability, mental illness, addiction, culture, or a player's lived experience.
This guide explains the mechanics without reproducing the source tables, then shows how to create original, playable consequences. Read Bouts of Madness for how a new side effect can arise, and Indefinite Insanity for the longer state in which these effects matter most.
Hot Take
Rolling on the sample tables is the weakest way to use this rule. Half the entries have nothing to do with the scene that caused them, and a fear of vegetables after a ghoul attack is a joke the table will forget by next session. Pick the consequence with the player and tie it to the horror. A reporter who compulsively documents every doorway after a haunted hotel hands the group clues, complications, and a reason to care.
What the Terms Mean in Play
A phobia points the investigator away from a subject. It may center on a place, sensation, object, situation, memory, or symbolic reminder of what frightened them. A mania points the investigator toward a subject. It may be an urge to collect, check, record, arrange, protect, learn, repeat, or reach something.
The game divides their impact by the investigator's current state. While the investigator is otherwise sane, a phobia or mania is primarily a roleplaying trait. The player can decide that their claustrophobic scholar still enters the tunnel because a companion is trapped inside. The trait can color the decision, but it does not mechanically prohibit action.
While the investigator is in underlying insanity, the same trait gains force. Direct exposure to the phobia's subject causes panic. Direct exposure to the mania's subject creates an obsessive response. This is a pressure on the scene, not a claim that every person with a fear or compulsion behaves the same way.
The affected state matters. A side effect can survive in the investigator's backstory after recovery and remain an interesting detail, but its specific penalty-die mechanics are tied to being insane under the rules. Do not carry a temporary mechanical penalty forward just because a note remains on the character sheet.
When the Rules Apply
New phobias and manias usually arise from a bout of madness: two of the ten results on each bout table grant one, and each time an investigator has a bout the Keeper may amend or add a backstory entry. The Keeper may roll on the sample tables or choose an appropriate result, but a collaborative choice is usually better. The consequence should connect to the triggering event and leave room for the player to make decisions.
Keep the timeline clear:
- An investigator becomes temporarily or indefinitely insane.
- The initial bout of madness establishes an immediate response.
- A phobia or mania may be added as a backstory consequence.
- After the bout, the investigator has player control again during underlying insanity.
- Direct exposure to the relevant subject can apply the phobia or mania rules while that underlying state lasts.
This avoids a common mistake: treating a newly added trait as a permanent command that the player must obey forever. It is a story hook. The active mechanical consequences depend on the investigator's state, the stimulus, and the table's agreed portrayal.
Phobic Responses While Insane
During underlying insanity, close physical exposure to the subject of a phobia causes panic. The investigator wants to avoid the source. For actions other than fighting or fleeing, the investigator takes one penalty die while exposed. This penalty does not apply to Sanity rolls or reality checks.
That rule creates a practical choice. A photographer with a fear of enclosed spaces may fight an attacker in a cramped tunnel, flee toward the exit, or attempt another action such as picking a lock with a penalty die. The character is not automatically frozen, and the player still chooses what to attempt.
Use exposure narrowly and fairly. A fear connected to drowning can matter on a stormy pier, in a flooded cellar, or while crossing a bridge during a chase. It should not impose a penalty for the entire session because someone mentioned a river at breakfast. State when the stimulus is present and state when the penalty ends.
The player can portray panic in many ways: checking exits, asking others to lead, refusing to touch an object, becoming terse, or taking a reckless route away from the trigger. None requires exaggerated performance. A small, consistent response is often more unsettling and more useful to the group.
Manic Responses While Insane
During underlying insanity, exposure to a mania's subject creates an overwhelming urge to indulge it. If the Keeper prompts behavior appropriate to the obsession, the investigator takes one penalty die on all dice rolls until the compulsion has been indulged in some way or the character is well away from the stimulus.
The broader penalty reflects distraction. A collector who becomes fixated on a specific symbol may struggle to notice a guard, drive a car, or negotiate with a witness until they have copied the symbol, taken a rubbing, or left the room. The player still decides how to satisfy the urge within the fiction, and the Keeper should accept reasonable, low-harm solutions.
Avoid making indulgence a trap. If the mania involves records, let the investigator make a sketch rather than steal the only evidence. If it involves an object, let them secure it in an evidence bag rather than demand that they endanger the party. The goal is to create tension between a character's immediate need and the group's plan, not to force a destructive action.
Be especially cautious with themes involving substances, self-injury, sexuality, eating, or violence. The game does not need them to create cosmic horror. If a table explicitly chooses such material, establish clear limits before it appears and preserve the player's ability to redirect the scene.
Create a Consequence That Belongs to the Story
Before choosing a phobia or mania, answer four questions together:
- What was the horror's image or idea? The consequence should have a visible connection to the triggering scene.
- What does this investigator value or fear losing? Use a backstory entry, a professional habit, or an established relationship.
- What action will the consequence create? It should produce a decision rather than a label.
- What is off limits? Confirm any boundaries before the result becomes recurring material.
Suppose an antiquarian hears a dead friend's voice through a gramophone. A generic fear of animals has no relationship to the scene. A fear of recorded voices, or a compulsion to catalog every recording before listening, gives the next case an immediate hook. The investigator may avoid a vital message, insist on documenting it, or recruit a companion to handle the machine.
Write the result as a sentence in the backstory, not only a medical-sounding name. "Never listens to a voice alone after midnight" tells the table how the story changes. "Must make a copy of every impossible recording" is a practical compulsion. Both are easier to use than an unexplained label.
Original Phobia Patterns
Instead of copying from a list, choose one of these patterns and tie it to the investigation:
- Place avoidance: A location type now feels unsafe, such as sealed rooms, waterfronts, hospitals, or upper floors.
- Sensory avoidance: A sound, smell, texture, color, rhythm, or temperature recalls the horror.
- Evidence avoidance: The investigator cannot bear a particular kind of photograph, artifact, language, or account.
- Social avoidance: A class of encounter feels dangerously deceptive, such as authority figures, strangers in uniform, or people who repeat a phrase.
- Pattern avoidance: The investigator fears a shape, arrangement, number, or recurring symbol connected to the event.
Give the response a scale. A mild version might make the investigator ask someone else to enter first. A stronger version during underlying insanity brings the penalty die and the need to flee or fight. The same concept can recur without flattening every scene into the same joke.
Example: After a flooded crypt, Celia develops a fear of still water reflecting a ceiling. While otherwise stable, she covers mirrors in hotel rooms and dislikes ponds. While in underlying insanity, entering a room with a black basin of water imposes the phobia's penalty on actions other than fighting or fleeing until she leaves or the basin is covered. This is specific, visual, and connected to the case.
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See Who's Running Call of CthulhuOriginal Mania Patterns
For a mania, choose an urge that creates work, risk, or a choice rather than an excuse to derail the party:
- Documentation: The investigator must copy, photograph, map, or count something before moving on.
- Protection: They need to preserve a person, object, room, or ritual from an imagined threat.
- Completion: They feel compelled to finish a phrase, arrangement, research task, route, or pattern.
- Acquisition: They need to collect samples, names, keys, clippings, or other evidence.
- Verification: They must check a fact, a lock, an alibi, or a repeated sequence until it feels certain.
Good manias allow several ways to indulge the urge. A journalist fixated on documenting doors can sketch them, dictate notes to a companion, or photograph them. The group chooses how much time and attention to spend. That choice is the scene; forcing the character to vandalize every door is not.
Example: After discovering a hidden tunnel plan, Arthur becomes compelled to ensure that every route has an escape path. In a normal period, he asks too many questions about exits. During underlying insanity, a blocked corridor or unfamiliar floor plan creates an obsessive response. He has a penalty die on all actions until he marks a route, secures a guide, or leaves the area. The compulsion adds tension without making Arthur incompetent.
Delusions and Reality Checks
Underlying insanity can also involve delusional sensory information. The Keeper may describe something the investigator seems to see, hear, smell, or feel, especially if it reflects the character's backstory. Use this with purpose. A late spouse's voice on a telephone is a more playable complication than telling the player every coat rack is a monster.
When a player suspects a perception may be false, they can call for a reality check: a Sanity roll. On success, the Keeper describes what the investigator actually perceives. The investigator becomes resistant to further delusions until losing SAN again, so a successful check should settle the question rather than invite repeated tricks.
On failure, the investigator loses 1 SAN and the delusion remains. If they are in underlying insanity, that loss immediately triggers another bout of madness. This makes reality checks meaningful: they are a way to challenge a frightening perception, not a free lie detector.
If the apparent thing would normally cause SAN loss, the player can either accept it as real and make the normal SAN roll or attempt a reality check. A successful reality check dispels the false threat and avoids the normal loss. A failed check causes the 1-SAN loss instead, then leads into a bout if the investigator is vulnerable. Explain those options before asking for a roll.
Psychoanalysis and Longer-Term Change
Successful Psychoanalysis can let an investigator temporarily ignore a phobia or mania or see through a delusion. It is a brief tool for a difficult scene, not a way to delete the condition with one skill roll. A supportive NPC or investigator can use it to help a companion enter a tunnel, set aside an obsession long enough to escape, or recognize that a frightening perception is false.
Longer-term removal belongs in the recovery process. At the end of a month, therapy may be used to remove a phobia or mania using the same general treatment procedure as indefinite-insanity recovery: a successful treatment roll followed by a successful SAN roll removes the backstory entry. This replaces the normal SAN gain for that treatment. Failure provides no benefit, and a fumble causes the stated setback.
Do not rush to erase every consequence. Some players may want the investigator to keep a milder trait after recovery because it has become part of the character. Others may want a clean end. Ask, then reflect the answer in the campaign notes. The rules give a procedure; the table decides the story value.
Player Guidance
Offer both a boundary and a hook. "I am comfortable with a fear related to places and sounds, but not contamination or medical treatment." "My investigator is proud of being organized, so an urge to document things would fit." This lets the Keeper create something personal without guessing at sensitive material.
When the effect is active, choose a behavior other players can see and respond to. Ask someone else to hold the lantern. Insist on copying a symbol. Refuse to cross a particular threshold until a companion checks it. The behavior should create a choice, not a demand that everyone stop playing while you repeat the same action.
Use a reality check only when you want the uncertainty resolved. On success, accept the Keeper's clarified description. On failure, lean into the next bout or ask for a fade-to-black if the content no longer feels good to play. You can revise a backstory consequence between sessions; nothing about a random roll outranks table consent.
Keeper Guidance
Do not roll a long list until you find a result that sounds entertaining. Start with the case, the character, and the player. A short choice between two fitting consequences often produces more engagement than a random result and avoids topics the group would rather not include.
State the mechanics when a stimulus appears. For a phobia: "You are in close proximity to the source, so actions other than fighting or fleeing take one penalty die while you remain exposed." For a mania: "This object is the stimulus; until you indulge the urge or leave it, you take one penalty die on rolls." The player should not have to infer a penalty from atmospheric narration.
Accept safe, plausible ways to satisfy a mania and make exits available for a phobia. You are creating pressure, not mandating a specific failure. Give companions ways to help through planning, reassurance, Psychoanalysis, or simple practical support.
Finally, keep the portrayal grounded. Avoid framing fears or compulsions as moral weakness, comedy, or evidence that an investigator is dangerous. The horror comes from the impossible thing that distorted a familiar part of a person, not from ridicule of that person.
Phobia and Mania Checklist
When creating the consequence:
- Tie it to the triggering horror and an established character hook.
- Confirm the player is comfortable with the theme.
- Write a specific backstory sentence that suggests future actions.
- Choose an effect with more than one safe, playable response.
When the stimulus appears during underlying insanity:
- For a phobia, apply one penalty die to actions other than fighting or fleeing.
- For a mania, apply one penalty die to all rolls until the urge is indulged or the stimulus is left behind.
- Do not apply the phobia penalty to Sanity rolls or reality checks. The mania penalty applies to all rolls.
- Explain when the stimulus is present and when its effect ends.
When perception is uncertain:
- Offer the choice between accepting the apparent threat and making a reality check.
- On a successful reality check, give the true description and stop repeating the delusion until further SAN loss.
- On a failed check, apply the 1-SAN loss and resolve a new bout if underlying insanity is active.
- Revisit the consequence during recovery or between chapters with the player.
Phobias and manias work when they make an investigator's fear legible without reducing them to it. Keep the consequence specific, collaborative, and connected to the mystery. Then it will add tension to the next scene instead of becoming a list entry everyone forgets.
