Why do coins have ridged edges? The clever reason dates back centuries

Look closely at the change in your pocket and you'll spot something easy to overlook: some coins have perfectly smooth rims, while others are lined with fine grooves. Most people assume this is just decoration. Actually, it's a centuries-old engineering trick that once protected the very value of money itself.A solution to an old problemAccording to various reports, the story starts in Europe during the 1500s and 1600s, back when coins were struck from actual gold and silver. Because the metal itself was valuable, criminals found a sneaky way to profit without destroying the coin outright. This scheme was called "coin clipping." Someone would shave a sliver of precious metal off the rim - so thin it was barely noticeable - and pocket it. Meanwhile, the clipped coins kept circulating, now lighter than they were supposed to be.The scale of this fraud eventually became a real economic threat.