Building Threats and Encounters
Threats are not only enemies. They are anything that forces a meaningful choice: a locked archive, a deadline, a hostile witness, a wound, a cult's influence, or a creature that cannot be fought conventionally.
Creatures
A creature entry should communicate its role at a glance. Give it characteristics, Hit Points, movement, armor, two to four relevant skills, attacks, Sanity cost, habitat or organization, and special rules. The existing creature type is intentionally broad enough for predators, cult servants, alien intelligences, and supernatural entities.
Use threat bands as a starting point, not a rigid challenge rating:
| Threat | Typical HP | Typical Sanity cost |
|---|---|---|
| Minor | 3–8 | 1d3 |
| Major | 9–15 | 1d6 |
| Greater | 16–25 | 1d8 or more |
| Cosmic | 26+ or effectively unkillable | 1d10 or more |
A frightening creature needs a pattern and a way to matter outside combat. Give it a tell, a desire, a limitation, and a consequence for learning about it. Resist making every weakness “deal more damage.” Cold iron, a forbidden name, a location, a ritual, or a social obligation can all be better weaknesses.
Combat balance
Combat uses one action and movement per turn. Attacks are skill checks; critical attacks maximize damage and ignore armor. Armor is flat damage reduction and does not stack. Major wounds occur when one hit deals at least half maximum HP; reaching 0 HP causes unconsciousness and bleeding, while negative CON is death.
These rules make firearms and Mythos attacks dangerous. Build encounters with exits, cover, negotiation, or objectives other than killing. A fight should change the investigation even when the investigators flee.
Sanity and magic
Sanity begins at POW and cannot exceed that starting maximum. A Sanity check uses POW × 5, adjusted by the current Stability modifier and the horror's difficulty. A failed check pays the full cost; success pays the minimum; fumbles are especially dangerous. Losing one-fifth or more of maximum Sanity in one encounter triggers temporary insanity, and zero Sanity creates indefinite insanity.
Spells use POW × 5, require knowledge and fictional components, spend Magic Points, and usually cost Sanity. A spell is an invitation to consequence. Design magical effects with a price, a requirement, a visible or discoverable signature, and a failure that attracts attention or creates a new problem.