Occultism and Hidden Lore

Below are some clarifications and distinctions regarding occultism and related knowledge skills.

None of these knowledge skills provide any practical ability to actually do anything, nor should they be presumed to represent or replace other skills, no matter how closely related. Expert Skill (Pneumatology) does not allow you to perform exorcisms, for example. Expert Skill (Demonology) does not give you the skills or knowledge to summon a demon. Similarly, Hidden Lore (Demons) does not allow you to banish or otherwise actively deal with demons, just as Hidden Lore (Spirits) doesn't let you banish or exorcise ghosts. These skills give you knowledge and can be used to provide bonuses to actionable skills. A successful roll against Hidden Lore (Demons), for example, may provide you a bonus for the use of Banish or Exorcism.

The difference between Expert Skill and Hidden Lore is really more a matter of flavor. Hidden Lore represents stuff learned through the study of old books, and Expert Skill represents stuff learned by experience or academic study. Think of them as representing the classic tension between "book smarts" and "street smarts" when it comes to the supernatural.

Occultism

Occultism is the general study of the mysterious and the supernatural. Occultism represents knowledge contained in publicly available or otherwise known sources, some of which may be rare or obscure but do not amount to Hidden Lore. Specialization should be represented by Expert Skills. See GURPS Basic p. 212 and GURPS Horror p. 29 for more information.

Expert Skills

Expert Skills should be used to represent knowledge more specific areas of occultism such as Cryptozoology, Demonology, Pneumatology, Ufology, and Vampirology. Specialization is required. While this study also derives knowledge from publicly available sources, the expert has spent considerable time in focused study of a particular subject. Descriptions of these specializations may be found in GURPS Horror, p. 29.

Hidden Lore

Hidden Lore is knowledge that is lost, deliberately hidden, or simply neglected. Narrow specialization may be required. Sources of Hidden Lore are not publicly available and in some cases are not even known to those who do not possess the skill. Any occultism expert skill likely has a hidden lore parallel, but there are areas of hidden lore unknown to the general occultist or even expert, and there may be areas of specificity within the known areas of knowledge. Acquiring or improving Hidden Lore requires a reliable source of relevant information. See GURPS Basic p. 200 for a detailed description and some examples.

None of these skills provide any practical ability to actually do anything, nor should they be presumed to represent or replace other skills, no matter how closely related. Expert Skill (Pneumatology) does not allow you to perform Exorcisms, for example. Expert Skill (Demonology) does not give you the skills or knowledge to summon a demon.