Ah, Clackers. A pair of acrylic balls attached to a string that you’d smash together repeatedly to make a satisfying (and slightly terrifying) “clack” sound. What could possibly go wrong?

Lawn darts were a staple of outdoor fun in the ’70s and ’80s, but they came with a serious safety caveat—each dart was essentially a weighted spear. The goal of the game was to toss these ...