¡Niños!

User summary:

Characters in the game are Grade-School age children (Grades 1-6) with four Attributes (roughly, Aplomb, Mischief, Rubber, and Charming/Hateful) with values of 1-5 and ten Skills (roughly, Seek, Battle, Run, Manipulate, Hide, Boy Stuff, Girl Stuff, Climb, Stable Vehicles, Tricky Vehicles) with "Grade" of 0-3. The game mechanic uses an unusual series of D6 rolls with special results based on the "Grade" of the appropriate Skill.

Although the game can easily be played with children, it nevertheless is a full-featured system that supports long-term campaign play.