Trail of Cthulhu

Trail of Cthulhu is an investigative horror role-playing game published by Pelgrane Press in which the players' characters investigate mysterious events related to the Cthulhu Mythos. It was designed by Kenneth Hite using the Gumshoe System, which was created by Robin Laws. "Trail of Cthulhu" is based on the "Call of Cthulhu" role playing game under license from Chaosium.
History.
"Trail of Cthulhu" features the Gumshoe System, which was previously used by Pelgrane Press in "The Esoterrorists" (2006) and "Fear Itself" (2007). The game was printed "by arrangement with Chaosium", the publishers of the earlier "Call of Cthulhu" role-playing game. "Trail of Cthulhu" has been supplemented by print supplements – mainly by Robin Laws and Ken Hite – plus a number of PDF adventures.
Setting.
"Trail of Cthulhu" is based on the writings of H. P. Lovecraft. It is set during the historical 1930s of our own world, but with fictional characters and locations (such as Professor Armitage and Arkham), and the menacing Cthulhu Mythos present in the background. Horrid monsters lurk in dark and forgotten places, while fiendish cults worship Great Old Ones and Outer Gods through blasphemous rituals. Ordinary people that are drawn into and forced to confront this world of mystery and horror risk not only their physical well-being, but their mental health as well.
The game supports two styles of play, though their elements are fully interchangeable. The "Purist" style aims at intellectual horror and cosmic dread, detailing ordinary people’s futile struggle against the Cthulhu Mythos. Death and (more importantly) insanity are not only constant threats for purist characters, they are almost inevitable. The "Pulp" style is intended for a more adventurous, thrilling location style of play, where brave heroes battle the denizens of the Cthulhu Mythos. Though danger is certainly present, pulp characters are more able to survive the horrors they encounter.
Gameplay.
Each player controls an Investigator, a fictional character that slowly uncovers the mysteries of the setting, while the Lore Keeper describes and controls the setting and its inhabitants. The players describe their character’s intended actions, making them interact with the setting and its inhabitants. Outcomes of these actions are either determined by the rules of the game or chosen by the Keeper. The rules combine a "narrative" approach to investigation with a simple approach to resolving physical actions including combat. The former is resolved by dialogue and players choosing to expend resources (Spends of Pool Points), the latter is resolved by rolling dice against target numbers or opposed rolls.
Scenarios.
Playing "Trail of Cthulhu" typically involves a mystery for the players to solve through the actions of their characters. The Keeper either prepares a scenario of his own, or buys a premade one. A scenario contains plot, character, and location details that form the mystery. As the player characters interact with the scenario's contents, they uncover clues that move them from scene to scene, eventually giving them information needed to solve the mystery.
Campaigns.
A campaign is a continuing storyline or a set of scenarios that are somehow linked together, usually with recurring characters and locations. Typically the players will continue to use the same characters, giving the characters time to change and evolve as the horrors of the Cthulhu Mythos affect them.
System.
The Gumshoe System is centred on the idea that investigative scenarios are not about finding clues, they are about interpreting the clues that you find. The system therefore makes finding clues all but automatic. If a scene contains a clue, and a player character uses an ability that relates to the clue, the clue will be found. There are no dice rolls involved in finding clues.
Occupations.
All player characters have an occupation that they might or might not continue with as they uncover the Cthulhu Mythos. Each occupation has a number of occupational abilities that are bought at a reduced cost when spending build points during character creation. Each occupation also has a special ability.
Drives.
Each player character has Drive, a motivation that keeps him or her going where normal people would have given up in the face of horror. Player characters that act against their Drives will lose Stability, while player characters that follow their Drives will refresh lost Stability.
Abilities.
Both investigative and general abilities have been adapted to better suit the 1930s era. The number of investigative build points have been slightly reduced as a compensation for the reduced cost of occupational abilities. Build points for general abilities have been increased since there are more general abilities in "Trail of Cthulhu". For Pulp style play, it is suggested that general build points could be increased even more.
Health & Stability.
In Purist style play, Health and Stability cannot exceed 12.
Sanity.
As a complement to Stability, an ability called Sanity has been added as a long-term measurement of a player character's mental health. For each 3 full rating points in Sanity, a character must have one Pillar of Sanity; a human concern that he or she believes and trusts in.
Just as in "Call of Cthulhu", a rating in the Cthulhu Mythos ability reduces player characters' maximum Sanity.
In Purist style play, lost Sanity is never refreshed, while Pulp style may allow player characters to refresh some Sanity if they successfully complete scenarios.
Improving the Character.
"Trail of Cthulhu" allows player characters to reassign up to 2 build points between scenarios. In Purist style play, player characters do not receive new build points after a scenario is completed.
Magic.
"Trail of Cthulhu" introduces a magic system to the GUMSHOE System. It includes both spells and rituals, though the difference is more in theme rather than rules. Using magic in "ToC" will quickly drain away a player character's Stability.
Products.
"Trail of Cthulhu" received two silver ENnie Awards for Best Rules and Best Writing (2008), as well as an honorary mention for Best Product.
"The Armitage Files" received a silver ENnie Award for Best Adventure (2010).
"Bookhounds of London" received a silver ENnie Award for Best Cartography (2011).
"The Book of the Smoke - The Investigator's Guide to Occult London" received a gold ENnie Award for Best Writing, and "Cthulhu Apocalypse: The Apocalypse Machine" received a gold ENnie Award for Best Electronic Book (2012).
Reception.
Game designer Shannon Appelcline describes the game's appearance: ""Trail of Cthulhu" was released as a handsome hardcover volume, over twice as long as either of the previous Gumshoe games. Two-toned printing and beautiful gray-scale artwork helped to make "Trail of Cthulhu" one of the most attractive and notable books that Pelgrane had ever produced."