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 dates from a time when the Celts were mainly a pastoral people, dependent on their herds. Some Neolithic passage tombs in Ireland are aligned with the sunrise around the times of Samhain and Imbolc. These include the Mound of the Hostages ("Dumha na nGiall") at the Hill of Tara, and Cairn L at Slieve na Calliagh. In medieval Ireland the festival marked the end of the season for trade and warfare and was a time for tribal gatherings. These gatherings are a popular setting for early Irish tales. Irish mythology was originally a spoken tradition, but much of it was