Samhain step from guising to playing pranks". Playing pranks at Samhain is recorded in the Scottish Highlands as far back as 1736 and was also common in Ireland, which led to Samhain being nicknamed "Mischief Night" in some parts. Wearing costumes at Halloween spread to England in the 20th century, as did the custom of playing pranks, though there had been mumming at other festivals. At the time of mass transatlantic Irish and Scottish immigration, which popularised Halloween in North America, Halloween in Ireland and Scotland had a strong tradition of guising and pranks. Trick-or-treating may have come from the custom
Samhain tells how each Samhain the men of Ireland went to woo a beautiful maiden who lives in the fairy mound on Brí Eile (Croghan Hill). It says that each year someone would be killed "to mark the occasion", by persons unknown. Some academics suggest that these tales recall human sacrifice, and argue that several ancient Irish bog bodies (such as Old Croghan Man) appear to have been kings who were ritually killed, some of them around the time of Samhain. In the "Echtra Neraí" ('The Adventure of Nera'), King Ailill of Connacht sets his retinue a test of bravery on