Twenty ideas, inside and out.
Two things decide it: is it dry outside, and do they need to run or wind down? Find the pair below, pick one, and you're playing in a minute.
Look out the window, then at your kid. Dry and bouncing off the walls: a water balloon toss or a bike slow race. Raining: the floor is lava, then a blanket fort.
The ones that need almost nothing and start in a minute. Every idea here needs a rope, a hose, a blanket, some paper or nothing at all, and comes with a one-line way to play it.
Kids around 3 to 10. The outdoor list was picked for 7 to 10, but ice excavation, the leaf pile and paper boats work for a 3 year old too. Every idea says how many kids it takes.