The Christian Halloween adopted traditions from a much older Celtic holiday. More than 2000 years ago, the Druids observed a festival called Samhain, during which the god of the dead, they believed, came back to earth accompanied by ghosts and goblins. Sound familiar? The Celtic people wore animal skins and animal heads to hide from these evil spirits, and Druid priests burned sacrifices to appease the spirits.

Today's popular Halloween colors recall the orange bonfires against the black nighttime skies. Costuming expanded from animals and spooky creatures to saints and, as we see today, to personalities in the popular culture.

In addition to the Druid influence, Roman harvest festivals of the first century A.D., especially one honoring Pomona, the goddess of fruit, also put their stamp on the celebration.

Bobbing for apples is recorded in medieval manuscripts. Today's popular Halloween imagery of pumpkins and cornfield mazes reflects the Roman tradition of celebrating a good harvest.

The most common tradition in today's Halloween, trick-or-treating, is a reenactment of Irish beggars going to the homes of the rich on All Hallows Eve to ask for food or money. If the rich refused, evil spirits -- so the beggars said -- would destroy their homes.

Trick-or-treating became widespread in America in the 1940s, according to Lucille Recht Penner in Celebration (Simon & Schuster, 1993). Costumed children went house-to-house asking for small handouts, usually candy. In return, no tricks would be played.