Earth's magnetic field
Magnetic field that extends from the Earth’s inner core to where it meets the solar wind
Would a compass attuned to Earth's magnetic field be a bad gift for a Christmas elf??
Christmas elves work in Santa's workshop on the North Pole Magnetic compasses point to the North Pole  If you are on the North Pole a compass will not work
What do compasses do? Where do Christmas elves work? Would #1 not be effective if you are already at #2?