Basic Roleplaying System available on Open Game License

26 March 2020
Thanks Chaosium!

The Basic Roleplaying System is the set of rules we're all familiar with from Call of Cthulhu, Runequest and SuperWorld, amongst others.

Now, thanks to Chaosium, the system has been released for any designer to use for their game in the form of the Basic Roleplaying System Reference Document.

If that's all you needed to know, and you just want to dive into this newly open-sourced RPG system, then head over to the Basic Roleplaying SRD page on the Chaosium website.

For the uninitiated, the percentile system is fast, elegant, and is based off skills. The general rule is that, to succeed a roll, the player must roll lower than their skill on a D100.  Above is a failure. As with many systems there is a gradiation of success and failure. 

The system allows for clever thematic tricks like the Call of Cthulhu's sanity rolls. While the initial test for actually seeing an old great one ask you to succeed with a sanity roll (a stat that can be reduced through exposure to mind-bending horror events), the second test is an intelligence test. Here a failure is preferable (to the player, not to the story or the GM) as to pass the intelligence test means your character understands the horror of what they've seen, and that's all the worse. In Call of Cthulhu, being dumb can really help.

Now might be a great time to put together that RPG you've always wanted to write, and there's a whole system there for you to use right out of the box.

The original Basic Roleplaying System documents can be found here.

Basic Roleplaying System now Open Source


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