The GUMSHOE system, often known as the "GUMSHOE Engine", is a tabletop roleplaying Universal System created by Robin Laws for Pelgrane Press, and used in a number of Pelgrane's games. Pelgrane do not publish a standalone GUMSHOE rulebook; rather, the rules are revised and customised and integrated into each game where they are used.
GUMSHOE is designed more with storytelling than with simulation in mind, and as the name is intended to suggest, it is primarily intended to support detective and mystery stories. This intention is most visible in the rule which says that if a scene incorporates a "core clue" which is required to move the plot forward, and if any of the PCs involved have an appropriate ability, they find that clue automatically — and players are encouraged to make sure that their characters have a full range of investigative abilities between them. Hence, a mystery plot should never get bogged down by the lack of important clues.
A variant version of the system, GUMSHOE One-2-One, designed for games with one GM and just one player, has been used for a couple of supplements. GUMSHOE has no connection to the video game of the same name.
Pelgrane Press games using the GUMSHOE Engine include:
- Ashen Stars — A game of interstellar troubleshooters in a Space Opera setting.
- Born Robot — Robots safeguarding their communities from hazards and deadly glitches in Humanity's Wake.
- The Esoterrorists — In which the heroes are the Ordo Veritatis, who combat Esoterrorists, occult terrorists who oppose reality as we know it and unleash the unremitting horrors of the Outer Dark.
- Fear Itself — A game set in the same world but instead about ordinary people fighting creatures from the Outer Dark.
- The Book of Unremitting Horror is a supplement for both The Esoterrorists and Fear Itself, detailing entities of the Outer Dark.
- The Fall of DELTA GREEN — A prequel to Delta Green set in The '60s.
- The Gaean Reach — A short game based on the setting of Jack Vance's "Gaean Reach" books.
- Lorefinder — An adaptation of GUMSHOE for use with Pathfinder.
- Moon Dust Men — An alien conspiracy game set during the Cold War published as part of the Ken Writes About Stuff series.
- Mutant City Blues — Which takes place in a world where 1% of the population has gained super-powers, and the protagonists deal with crimes involving these powered people.
- Night's Black Agents — In which the heroes are modern-day independent secret agents who discover that the evil conspiracy they are fighting is actually run by vampires.
- The Dracula Dossier — An improvisational campaign.
- Night's Black Agents: Solo Ops — The GUMSHOE One-2-One version.
- Swords Of The Serpentine — A Sword and Sorcery fantasy game set in the sort of city that tends to show up in the genre.
- TimeWatch — A somewhat tongue-in-cheek Time Travel game.
- Trail of Cthulhu — Lovecraftian horror set in The '30s.
- Cthulhu Confidential — The GUMSHOE One-2-One version.
- The Yellow King — A multi-generational game about a world subjected to the reality-altering horror of the play from The King in Yellow.
Other games using the GUMSHOE Engine include:
- Achtung! Cthulhu — A WW2 Lovecraft setting from Modiphius Entertainment converted to use with GUMSHOE.
- Against the Unknown — A streamlined version of GUMSHOE for 1920s-set games, from Porcupine Publishing.
- Casting The Runes — A supernatural investigation game from Design Mechanism based on the ghost stories and tales of the supernatural by M. R. James.
- Bubblegumshoe — A streamlined version of GUMSHOE for playing teen sleuths solving mysteries in small American towns.
- Republic — A simplified version of GUMSHOE about politics and intrigue.
- Spookshow — A game from Scott Carter Games about a ghost hunting show where the ghosts are very real.
- What Remains — Solving crimes in Victorian London from Elementary Publishing.
The GUMSHOE Engine provides examples of:
- Crazy-Prepared: The Preparedness skill lets you retroactively have had something you need in your bag the whole time.
- Crossover: GUMSHOE games and sourcebooks frequently include conversion guides which allow you to easily mix-and-match their elements with other GUMSHOE games.
- Forensic Accounting: An available core character skill in some iterations of the system — necessarily, because the system is built to facilitate (and encourage) roleplaying detective work.
- Linked List Clue Methodology: The core mechanic of the system.
