A term used for the flame used to light the balefire.
Elf fire is created without the use of metals. In the old times, the town elders would keep the elf fire burning all year long, often as a hearth fire in the house of the mayor or an appointed keeper of the fire. It would be used to light the balefire at the end of the year, which in turn would be used to light a new elf fire from that year's village balefire.
Today, elf fire is sometimes used to refer to the fire used to light the balefire used at a compass round.