I've tried researching this one on my own and I've come up with several different answers depending on the site I'm checking. I'd like some solid information on obtaining unique charms in Diablo 2. There are three in total: Annihilus, Gheed's Fortune, and the Hellfire Torch.
Can I find unique charms while playing single player? If so, do they drop on a specific difficulty (Nightmare, Hell)? Details on all three would be helpful.