Can't see your coin in these photos. It is a Half Dollar not a half cent. Why do you think it is rare?
What is the error? Where exactly is it? We need to see clear photos out of the plastic. We need to see a close up of this error?
Nice misaligned die (MAD). Usually these don't carry a premium, but yours is dramatic enough that it may be worth a couple dollars to the right buyer. Cool find. Edit to add: Notice that the reverse shows the normal alignment. A true off centered strike would have both sides showing the same appearance
It is strange that the reverse is in alignment. Just for my own education @mikediamond. Since the reverse in most cases is the hammer die, and the collar is over the anvil die, how does the obverse get so misaligned and still be in collar? Would this be a case where the hammer was the obverse die?
It's called a Misaligned Die (MAD). One die is installed slightly off center, while the other die is installed correctly. You can usually find cents and dimes exhibiting MAD, and it doesn't normally add any extra value to the coin. The OPs coin has quite a bit of misalignment and therefore, it may be worth a minor premium over face value. It IS NOT an off center error. An off center strike is caused by the planchet not being centered in the chamber. Both sides will show the same amount of off-centering. One side off center = MAD Two sides off center = Off Center strike Hope this helps
I know all of that. Please reread my post. If the usual setup is used, the blank would be resting on the obverse die with the collar die around it when it is struck with the reverse die. For the obverse to be so misaligned, it couldn't be in collar, or at least I wouldn't think so, unless the set up were reversed and the obverse was the hammer die.