Lawn games like croquet, bocce ball, beanbag toss and horseshoes are simple to set up and easy for kids and adults to play during cocktail hour and after dinner. Not a bad idea when there's a gap between wedding & reception. This might be kinda fun.
Fun outdoor game for kids and adults. Use frisbees and paint the back side of them. How to make a unique bean bag toss game from terra cotta pot saucers and a printable (which you can get for free by clicking through!
14 Insanely Awesome Backyard Games to DIY Right Now