Send young guests home tired instead of wired with these indoor party games that really get kids moving. Depending on how many guests you have (and how many breakables), these games can be played indoors or in a garage, basement, or park shelter.
Bubble-icious: Give kids socks to wear on their hands. Then blow bubbles and have players try to catch them. For an extra challenge (e.g., for older kids), have players sit in a circle and try to pass a bubble from person to person. How long can they keep it going?
Hula Hoop It Up: Give players hoops and have them spin as long as they can. If they drop the hoop, they're out. If you don't have enough room for everyone to play at the same time, have a series of head-to-head competitions. (See a video demo.)
Shoebox Race: Tape lids to shoeboxes and cut slits in the top (about 1 inch wide and 4 inches long). Have kids slip them on for a bigfoot race (make it a relay if you don't have enough space or shoeboxes to go around). This game can adapt to many themes, like outer space (paint boxes silver and call them astronaut boots), animals (decorate boxes to look like hooves or paws), or race cars (have kids draw wheels and racing stripes on the boxes). See a video demo.
One If By Land, Two If By Sea: Mark a line on the ground using chalk or painter's tape. Choose one person to call out the commands "land," "sea," or "air." Have the rest of the players stand in front of the line, shoulder to shoulder. If the caller says "land," everyone jumps behind the line. If the caller says "sea," everyone jumps over the line. If the caller says "air," everyone jumps straight up. (For an extra challenge: If the caller says "land" or "sea" twice in a row, don't move on the second call.) Anyone who jumps on the line or makes a mistake is out.
Classic Indoor Party Games: Don't forget these old favorites. They are easy to do and endlessly variable. Make them harder or easier, competitive or not. Or modify to fit your birthday party's theme: For example, swap paper or cardboard targets for seats, and musical chairs can become musical frogs on lily pads, dogs in doghouses, butterflies on flowers, bumblebees in hives, and so on.