Ancient Chinese invented them. A Chinese Army—expanding west met a Roman Army Expanding East and fought a battle. It was a draw. They didn’t even know who they were fighting! But the Romans captured some crossbows and sent them back to Rome. There they improved on them—but it wasn’t enough to stop the fall of Rome but brought Crossbows into the west. Thank you Ancient China. Want to make them more deadly? Dip the point in a bit a excrement, this will cause life threatening inflections. The bad guy may kill you, but you will have revenge when he dies of slow and painful blood poisoning!