System Intent

This is a Basic Roleplaying–inspired d100 horror system about ordinary investigators confronting knowledge and forces that should remain hidden. Its design target is not heroic certainty. Characters are capable enough to investigate, fragile enough to fear consequences, and specialized enough that a group needs one another.

The central loop

A strong scenario moves through five beats:

1. Hook — Give investigators a reason to care.
2. Leads — Put several discoverable paths in front of them.
3. Pressure — Add time, opposition, cost, or incomplete information.
4. Revelation — Expose a truth that changes what the investigators believe.
5. Confrontation — Let them choose between danger, retreat, sacrifice, or compromise.

The rules support this loop with three kinds of pressure: percentile uncertainty, physical wounds, and Sanity loss. Do not make every scene a roll. Roll when failure changes the situation; otherwise provide the information or let the investigators act.

What makes an entry fit

New content should reinforce at least one of these promises:

• Investigation matters. Skills reveal, connect, or interpret evidence.
• Preparation matters. Tools, contacts, research, and positioning improve odds.
• Violence is costly. Combat is decisive but should not be the default solution.
• The Mythos has a price. Forbidden knowledge grants leverage while eroding safety, sanity, or humanity.
• Characters remain distinct. A new option should create a useful specialty, not make existing specialists irrelevant.

When adding a rule, prefer a small modifier, an opposed check, a cost, or a new consequence over a new subsystem. The game already has a resolution engine; use it.

Tone and scope

The default setting assumes early twentieth-century investigation, social barriers, imperfect medicine, limited communications, and expensive travel. A different era can work, but update equipment, occupations, access to information, and the meaning of Credit Rating together. Technology should change the problems investigators face, not remove uncertainty entirely.

Keep horror suggestive and consequential. The unknown is more effective when the reader can infer its scale. A creature, spell, or cult should have a motive, a tell, a weakness or cost, and a consequence beyond hit-point damage.