The jack-o’-lantern comes from Irish origins, of a carved vegetable holding a light to ward off evil. While often done with a pumpkin, they were traditionally carved from turnips.
The jack-o’-lantern is a hollowed out vegetable, carved with some kind of gruesome or terrifying face and lit inside with a candle. They were used to ward off evil spirits and demons that are able to cross to our world during the fall, especially at Samhain, which is at the end of October as the harvest ends. Some modern Halloween come from these older traditions, such as dressing up in costume after dark, to confuse the demons roaming the earth.
One legend attributes the origin of this tradition to a man called Stingy Jack, who tricked the Devil into a deal where he would never collect Jack’s soul. Details differ, but the consistent trait is that Jack somehow trapped the Devil using a cross and only let him free when the Devil agreed to the deal. When Jack did eventually die, Heaven wouldn’t take him, and the Devil couldn’t bring him to hell. The Devil tossed him a burning ember to guide him, and he wanders the earth for all time, using the coal to light a lantern carved from a turnip.
While designs of carved pumpkins differ, to create a true jack-o’-lantern you must carve a face, one that is truly terrifying or gruesome, and it must be lit by a candle. Any vegetable will do here, but a turnip is the better size if you intend on carrying the lantern, while a pumpkin is more ideal for protecting a building.
To create a lantern, you must do the carving yourself, and light the lantern yourself just at sunset for maximum effectiveness. So long as the lantern is correctly lit, it will continue burning until the sun rises. While the lantern is lit, the person holding it, or the house it sits in front of, cannot be approached by anyone with ill intent.
The jack-o’-lantern only works for protection in the fall, with its best protection during Halloween itself, and becoming less effective as time goes on afterwards. Powerful supernatural creatures, or people with less negative intentions, can overcome the protection it offers during these times.
Besides the physical limitations of a lantern carved from a vegetable, a jack-o’-lantern is weakened if the vegetable it is in breaks down or decays. To maintain effectiveness during October, the month where the lantern is most powerful, having several and keeping a sharp eye out for rotting pumpkins is the best way to overlap protection