Jack o' Lantern - an ancient invention to ward off evil spirits this HalloweenJack Reznicki/CORBIS

1. It is an ancient Irish festival, created for Samhain, the day when the undead walk among us and we must ward off evil spirits.

2. It marked the end of the long days and the drawing in of winter. In the same way that the Celts celebrated Lughnasa, the festival when the harvest was brought in, Samhain represented the beginning of winter.

3. A favorite game was to blindfold the Irish person and ask them to place their hand on some Halloween items. A bowl of water meant emigration, a piece of earth meant a death in the family, a ring meant a wedding and so on.

4. One of the greatest short stories by James Joyce, ‘Clay,’ refers to this very custom when the main character touches the clay saucer but is quickly moved on by her worried relatives.

5. The ring was also hidden in the Barm Brack, the fruitcake specially made for the occasion. The person who got the ring-- if you didn’t swallow it-- had a happy marriage ahead.

6. Bobbing for apples is when couples try to bite an apple that is bobbing in a bowl of water. The symbolism was biting into the seed, which meant fertility in the year ahead.

7.  Meeting a red-haired woman was a bad omen especially for fishermen, but meeting one on Halloween was even more dire. A man had to turn around and go right back home, but funnily, a woman did not.

8. Orange and black, the colors of Halloween, are the colors of death in Celtic legend.

9. Druids were especially powerful at Halloween when the spirit world was closest. Their visions and predictions were most closely listened to then.

10. The custom of Halloween was brought to America by Irish famine emigrants in the 1840s.

*Originally published in October 2010.