Knowledge (Int)

Trained Only
This skill encompasses several categories, each of them treated as a separate skill. These categories are identified and defined below.
The number of Knowledge categories is kept purposely finite. When trying to determine what Knowledge skill a particular question or field of expertise falls under, use a broad interpretation of the existing categories. Do not arbitrarily make up new categories.
Check: A character makes a Knowledge check to see if the character knows something.
The DC for answering a question within the character's field of study is 10 for easy questions, 15 for basic questions, and 20 to 30 for tough questions.
Appraising the value of an object is one sort of task that can be performed using Knowledge. The DC depends on how common or obscure the object is. On a success, the character accurately identifies the object's purchase DC. If the character fails, he or she thinks it has a purchase DC 1d2 higher or lower (determine randomly) than its actual value. If the character fails by 5 or more, he or she thinks it has a purchase DC 1d4+2 higher or lower than its actual value. The GM may make the Knowledge roll for the character, so he or she doesn't know whether the appraisal is accurate or not.
The fourteen Knowledge categories, and the topics each one encompasses, are as follows.
Arcane Lore: The occult, magic and the supernatural, astrology, numerology, and similar topics.
Art: Fine arts and graphic arts, including art history and artistic techniques. Antiques, modern art, photography, and performance art forms such as music and dance, among others.
Behavioral Sciences: Psychology, sociology, and criminology.
Business: Business procedures, investment strategies, and corporate structures. Bureaucratic procedures and how to navigate them.
Civics: Law, legislation, litigation, and legal rights and obligations. Political and governmental institutions and processes.
Current Events: Recent happenings in the news, sports, politics, entertainment, and foreign affairs.
Earth and Life Sciences: Biology, botany, genetics, geology, and paleontology. Medicine and forensics.
History: Events, personalities, and cultures of the past. Archaeology and antiquities.
Physical Sciences: Astronomy, chemistry, mathematics, physics, and engineering.
Popular Culture: Popular music and personalities, genre films and books, urban legends, comics, science fiction, and gaming, among others.
Streetwise: Street and urban culture, local underworld personalities and events.
Tactics: Techniques and strategies for disposing and maneuvering forces in combat.
Technology: Current developments in cutting-edge devices, as well as the background necessary to identify various technological devices.
Theology and Philosophy: Liberal arts, ethics, philosophical concepts, and the study of religious faith, practice, and experience.
Try Again?: No. The check represents what a character knows, and thinking about a topic a second time doesn't let the character know something he or she never knew in the first place.
Special: An untrained Knowledge check is simply an Intelligence check. Without actual training, a character only knows common knowledge about a given subject.
A character can take 10 when making a Knowledge check, but can't take 20.
A character with the Educated feat gets a +2 bonus on any two types of Knowledge checks.
The GM may decide that having 5 or more ranks in a specific Knowledge skill provides a character with a +2 synergy bonus when making a related skill check.
Time: A Knowledge check can be a reaction, but otherwise requires a full-round action.