Ranked in these QuestionsQuestion Ranking
Pro Can be taught in less than 10 minutes
Risus has a very minimalist rule system that breaks down all actions to their core function. Risus comes with a super short, four page rulebook (available in many forms and formats) that's easy to read, includes examples and has a bit of humor thrown in to make the process or learning more enjoyable.
Pro A large following that provides a lot of content
A large amount of adventures, artwork, characters, clichés as well as optional rules can be found for Risus. An excellent resource for all aforementioned things as well as many others is Risusiverse, a fan-made website of all things Risus.
Pro Very flexible rules
Risus is not confined to a selection of pre-defined character-classes, settings or abilities. Characters are described via clichés such as Witch Doctor, Gambler, Musician with a number of dice assigned to each cliché that are then used in challenges that relate to the appropriate cliché.
Con Little guidance can be found for GMs and players
Some prior understanding of how an RPG is played and what is the role of the GM is required as the rules cover only the very core of the system.