32. Danish people are entitled to club a Swedish person over the head with a stick if they cross the frozen sea between the two countries
During the Dano-Swedish War of 1657-58, Sweden invaded Denmark in a most unusual manner. King Charles X Gustav of Sweden planned to cross to the Öresund strait by boat when waters were calm. However, in late January 1658, the Öresund froze solid, and he simply marched his army across. This took the Danes entirely by surprise: they weren’t expecting an attack until spring! Denmark panicked, and signed the Treaty of Roskilde, which yielded disputed territory to Sweden amongst other unfavorable conditions. Ever since it’s been legal for a Dane to club a Swede marching across the frozen Öresund with a stick.