Trick-or-treating is a customary celebration for children on Halloween. Children go in costume from house to house, asking for treats such as candy or sometimes money, with the question, "Trick or treat?" The word "trick" refers to a (mostly idle) threat to perform mischief on the homeowners or their property if no treat is given. In some parts of Ireland and Scotland children still go guising. In this custom the child performs some sort of show, i.e. sings a song or tells a ghost story, in order to earn their treats.
The term Halloween, originally spelled Hallowe’en, is shortened from All Hallow Even – e'en is a shortening of even, which is a shortening of evening. This is ultimately dervied from the Old English Eallra Hālgena ǣfen.t is now known as All Saints' Day.
A time of pagan festivities, Popes Gregory III (731–741) and Gregory IV (827–844) tried to supplant it with the Christian holiday (All Saints' Day) by moving it from May 13 to November 1.
In the 800s, the Church measured the day as starting at sunset, in accordance with the Florentine calendar. Although All Saints' Day is now considered to occur one day after Halloween, the two holidays were once celebrated on the same day.
Halloween costumes are traditionally those of monsters such as ghosts, skeletons, witches, and devils. They are said to be used to scare off demons.
There are several games traditionally associated with Halloween parties. One common game is dunking or apple bobbing, in which apples float in a tub or a large basin of water and the participants must use their teeth to remove an apple from the basin. A variant of dunking involves kneeling on a chair, holding a fork between the teeth and trying to drop the fork into an apple. Apples symbolized the years harvest. Another common game involves hanging up treacle or donuts by strings; these must be eaten without using hands while they remain attached to the string, an activity that inevitably leads to a very sticky face.
Some games traditionally played at Halloween are forms of divination. In Puicíní (pronounced "poocheeny"), a game played in Ireland, a blindfolded person is seated in front of a table on which several saucers are placed. The saucers are shuffled, and the seated person then chooses one by touch; the contents of the saucer determine the person's life during the following year. In 19th-century Ireland, young women placed slugs in saucers sprinkled with flour. A traditional Irish and Scottish form of divining one's future spouse is to carve an apple in one long strip, then toss the peel over one's shoulder. The peel is believed to land in the shape of the first letter of the future spouse's name.
Other foods associated with the holiday:
One custom that persists in modern-day Ireland is the baking (or more often nowadays, the purchase) of a barnbrack (Irish "báirín breac"), which is a light fruitcake, into which a plain ring, a coin and other charms are placed before baking. It is said that those who get a ring will find their true love in the ensuing year. This is similar to the tradition of king cake at the festival of Epiphany.
Some games traditionally played at Halloween are forms of divination. In Puicíní (pronounced "poocheeny"), a game played in Ireland, a blindfolded person is seated in front of a table on which several saucers are placed. The saucers are shuffled, and the seated person then chooses one by touch; the contents of the saucer determine the person's life during the following year. In 19th-century Ireland, young women placed slugs in saucers sprinkled with flour. A traditional Irish and Scottish form of divining one's future spouse is to carve an apple in one long strip, then toss the peel over one's shoulder. The peel is believed to land in the shape of the first letter of the future spouse's name. This custom has survived among Irish and Scottish immigrants in the rural United States.
Unmarried women were told that if they sat in a darkened room and gazed into a mirror on Halloween night, the face of their future husband would appear in the mirror. However, if they were destined to die before marriage, a skull would appear. The custom was widespread enough to be commemorated on greeting cards from the late 19th and early 20th centuries.
The telling of ghost stories was common traditions of Halloween.