ICE RPG (Index Card Easy Role-Playing Game)

From the PDF introduction:
The ICE RPG is designed as a barebones skeleton of a game for teaching new gamers the basics of roleplaying without them having to deal with a whole lot of numbers, stats, etc. An experienced gamer can learn the system in about 30 seconds and should be able to teach it to someone who has never played before in another 30 seconds.

The rules are sized to fit on one side of a 3" x 5" index card, and the character sheet fits on the other side. Cut along the dotted lines and tape each section to one side of an index card (or better yet, print on an adhesive label).