We've been busking games with three dice and no rules recently. Pick a setting - could be planets, could be castles, could be elephants in the jungle or guys in a bar.
More than three people is fine - we were the magnificent seven yesterday but I like three of four best for the rapidity.
Each turn, a player can ask for information and take an action. Information is about himself (eg an attribute) or his planet or castle or population or whatever. Lyu ran a planet with great scientific inventiveness (15 on 3d6) but awful engineering (rating 5 which fell to 4) - he sent half his population to another planet on a transporter ship of genius design but the engineering was hopeless - 7 days out from home world, the life support systems failed and he has seven day, maybe less, air left...
The actions arise from 2d6 - the saving roll - added to the attribute to reach 20 or 25 or...
As GM, you through in a few curve balls from time to time, and try to remember enough of what's gone on before to be consistent and wise.
We played in a Wendy's last Friday and kids were soon sidling up to hear the story unfold, fascinated by the part the dice played.
Who is the saint who invented dice?