Looking to solve eldritch mysteries and maybe go insane? Call of Cthulhu has what you need. Here's how to find a game.

Where to Play Call of Cthulhu

An actual 100-sided die is pretty unwieldy, so most players prefer to use percentile dice. These are two ten-sided dice, one of which has tens digits (00, 10, 20, 30, etc.) and the other has ones, that is, 0-9. Rolling them together produces a two-digit number, e.g. rolling a 70 and a 9 would be 79, rolling a 00 and a 3 would be 3, and rolling a 40 and a 0 would be 40.

There is some debate over whether 100 is rolled with a 10 and a 0 or 00 and 0, but the latter is generally accepted as more common, and it doesn't matter as long as your table is consistent!

Basic Roleplaying originated as a simplified version of RuneQuest, which was written by Steve Perrin. Greg Stafford produced the first official Basic Roleplaying book, and the system has been refined by other designers a few times since then.

Who created the Basic Roleplaying system?

Yes! The most basic version of Basic Roleplaying is available as a System Reference Document, or SRD, and made available on an open license to any creator who wishes to use it for their own work. 

Is there a free version of Basic Roleplaying?

Something similar to a critical success, called a "special success," exists in BRP. When a player rolls low enough on a skill roll that the result is one-fifth of the character's skill rating or less, the success is exceptionally effective, possibly going above and beyond what the player had hoped to achieve.

Are there critical successes in Basic Roleplaying?

Call of Cthulhu, which uses BRP as its game engine, is famous for its Sanity stat and the system by which player characters' sanity gradually erodes, until their contact with the Cthulhu mythos eventually drives them mad. It's a great example of a modular system that works with Basic Roleplaying, but might not exist in every game that uses it.

Does Basic Roleplaying have a sanity system?

Yes, BRP is a generic or "universal" system, meaning it doesn't assume a particular setting or theme. Its rules are designed to be flexible enough to work in any genre, and the breadth of games that use the system demonstrate how flexible it can be. Simply by adjusting what skills and equipment are available and what subsystems your campaign will use, you can customize BRP to work for nearly any setting.

Basic Roleplaying: Universal Game Engine

Basic Roleplaying, or BRP, is a generic, universal system for tabletop roleplaying games used primarily by the publisher Chaosium for its flagship games, most notably Call of Cthulhu and RuneQuest. At its core, Basic Roleplaying is a skill-based percentile system, meaning players roll a d100, trying to roll under their skill level, which is rated from 0-100%, depending on how skilled the character is in a given area.

Characters in BRP have seven stats: Strength, Constitution, Size, Intelligence, Dexterity, Power, and Appearance. They have several other characteristics derived from these, but more importantly, they have skills. What skills are available depend on the setting and theme of the campaign (you might see Library Use and Psychotherapy in Call of Cthulhu, for example, or Energy Weapon and Astronomy in a sci-fi game). These skills have ratings that determine how likely the character is to succeed at the average task in that field, expressed as a percentage. 

When players roll to use a skill, they roll two d10s to simulate a 100-sided die and aim to roll below their skill level. For a particularly difficult challenge, they might need to roll below half their skill level. Generally, lower rolls are better in BRP! Some versions of BRP also allow players to "push" failed rolls to try again, with the caveat that consequences will be worse if they fail a second time. Characters can occasionally improve their skills by using them, but higher skills are more difficult to raise than lower ones. A campaign can strike a more realistic tone with skill levels generally under 70-80%, or a heroic or even superheroic tone with skill levels up to 100% and above. There are also optional modules for magic and the occult.

BRP is probably best known in Call of Cthulhu, Chaosium's most popular tabletop RPG, but it's been used in fantasy, science fiction, and superhero games as well.

Browse Basic Roleplaying: Universal Game Engine TTRPGs Explore one-shots, campaigns, and homebrew adventures run by expert GMs across Roll20, Foundry VTT, Discord & more. Find your perfect game on StartPlayingGames!