2003 · ソースブック（プレイを拡張するルール／オプション）
Parapsychologist's Handbook
This monograph examines the history, methods, and theories of parapsychology for adventures set in the 1890s, 1920s, or contemporary era. It explains how to create a parapsychologist and investigate ghosts, hauntings, poltergeists, spiritualism, mediumship, and other unexplained phenomena. Guidance covers running a ghost-hunting or psychical research campaign, including non-Mythos entities, psychic powers, scenario ideas, and a Keeper’s guide to ghosts and poltergeists. Appendices provide sinister adventure seeds, new d20 psychic feats, and a bibliography of parapsychological literature from 1882–1930.
スキルベース（スキルを購入または獲得）属性／ステータス制（STR、CON、PERなど）ランダム属性生成（キャラクター作成時）
ゲーム情報（人数、プレイ時間、対象年齢、クレジット）の出典：BoardGameGeek。