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.
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.
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.
GRIN uses a a standard deck of playing cards to create a fast paced and deadly feel that evokes modern horror films. One of the best horror games made, its ideal for Halloween or horror movie nights.
Character sheet and rules take up only one page, which makes the game simple to understand and easy to reference while playing. Yet the rules still allow players to make interesting choices to avoid too much randomness.
Any material written for the d20 system can be used with the Microlite20 system. All creatures, items, monsters, spells, etc from any d20 SRD licensed resource are compatible with the Microlite20 system.
As Microlite20 is a stripped down version of the d20 SRD with the same classes, races, items and abilities, it will be easy to understand by anyone that has previously played a D&D game. Especially D&D 3.x.
Instead of rolling to perform actions such as swinging a sword, rolling is used for resolving intent with descriptions of actions left to players and GM to describe.
The Pool includes a system, called the Monologue of Victory, that allows a player to take over narration of the game in the event of a successful roll without the GM being able to interfere. As such using the system for complex plots may be difficult, because the player may remove an essential part of the story without knowing it.