"There's no such thing as a female wizard!"
There is a legend. The seventh son of the seventh son is truly a man of special powers. On the Discworld, the number eight holds even greater power (the eight spells in the Octavio, for instance, or octarine, the eighth color that only wizards can see.) So when the eighth son of the eighth son is born, a world of magic trembles. And when a dying wizard wants his staff to pass along to this child, prophesying that the child will be the greatest wizard ever, even Death feels unnerved. Imagine everyone's surprise then when the eighth son is actually a daughter!
In this third visit to the Discworld, the daughter of this foolish, foolish wizard inherits a staff of power with a mind of its own, and the strength of will to put it too use. But there are no female wizards, and this young lady, named Esk falls under the tutelage of one Granny Weatherwax, the most powerful witch in the Ramtops. In time Granny realizes that the power in this girl is far beyond what she's ever seen and decides that the girl should be educated among her fellow wizards, so its off to the Unseen University in Ankh-Morpork.
What I like about this story isn't the question of gender roles, sexism and equal rights for women, though Mr. Pratchett does a great job of addressing them in a serious, yet humorous way. For me the pleasure is in meeting Granny Weatherwax. A hard as nails woman who is powerful, yet rarely needs to use that power, she is described in another story as having "pride you can wrap a horseshoe around." Very much a believer in the ideas of equal treatment, she also clearly sees that she is above most people. And while she may get on your nerves, you know you won't dare to cross her. In Equal Rites, she isn't as full force as she will become, playing a relatively secondary role. But we do get a glimmer of the character that will take charge in future novels.
I've talked to people who argue this is their least favorite Discworld books, that the writing isn't what it could be, that the ideas are not fully developed. I can't argue, but on a second, or third reading, you see how he's developing this idea that the Discworld can poke fun at this crazy world of ours, while really examining serious ideas, in this case feminism. While it's not my favorite, I certainly recommend it.