Female? He told you he was female?”
“She,” Angua corrected. “This is Ank-Morpork, you know. We’ve got extra pronouns here.”
She could smell his bewilderment…
“Well, I would have though she’d have the decency to keep it to herself,” carrot said finally. “I don’t think it’s very clever, you know, to go around drawing attention to the fact.”
“Carrot, I think you might have something wrong with your head,” said Angua.
“I think you might have it stuck up your bum.
—  Terry Pratchett - Feet Of Clay
The Three Waves of Discworld

So I’ve been thinking for a while about the Discworld books, and how they can be divided up into three rough thematic phases; not based around the focal characters, but rather what the story is about.

The first wave, which begins with The Colour of Magic and I would say ends with Guards, Guards! or Faust Eric. These books are parodies of existing fantasy, and thematically spend a lot of time exploring the conventions of these stories, both mocking them and codifying them as fact for the Disc. We get a lot of witches and Rincewind books here.

Having set up the status quo, the stage is then set for the second wave to enter, starting with Moving Pictures. This is when Pratchett starts to branch out in terms out his parodies, and moves from fantasy parodies to other areas of society and culture, from the movies in Moving Pictures to shopping centres in that weird Reaper Man subplot, to guns in Men at Arms. Notably, all of these are based around external forces disrupting the status quo, and having to be set right. My favourite example of this is probably Jingo, where the external force disappears by itself when the island sinks back into the sea. Hogfather, Carpe Jugulum and Thief of Time all fit into this wave, which has kind of a fuzzy boundary with the third wave. 

Fantasy has always, as an overall genre, had a problem with the idea of growth and change. The idea of “Setting right what went wrong” and protecting the existing status quo has always been a major element in a lot of fantasy stories. “Restoring the true king” is a popular one which is lampooned by the character of Captain Carrot, but Discworld itself has, up to around 1996, had a problem with this itself (notably, the point of the Carrot subplot in Men at Arms is that he is the true king but delibrately chooses not to reveal himself in order to defend the status quo) Its plots, while often having some changes for individual characters, rarely allowed the setting itself to change, and the change that occurs is put right by the end.

The first book to sort of challenge this is probably the fantastic Feet of Clay, one of my favourites, where the role of the Golems is examined and by the end, the concept of a Golem owning itself is introduced. This is a major change for golems in the setting, but it isn’t really played with much here. The two books that really kick off the third wave come, fittingly, at the turn of the Millenium; 1999′s The Fifth Elephant, which examines dwarf politics, and the 25th Discworld novel, 2000′s The Truth, which is the first time we really see a persistant technological change in the setting. The newspaper set up by de Worde is a major factor in all the later books, and notably it is the protagonist of The Truth that is trying to disrupt the status quo with the creation of the newspaper. It isn’t films or rock music, which are eldritch abominations that must be stopped, but an organic and important change in the setting. This is the main theme of the third wave: the Disc is changed and shaped in lasting ways by the actions of the main characters, particularly on the wider social level. Cherry Littlebottom helps to change dwarf gender norms, goblins and orcs are introduced to society at large (admittedly in rather easy ways), and the biggest change of all is the introduction of everyone’s favourite conman, Moist Von Lipwig, who progressively creates or helps create the postal system, paper currency, and the first train network. In the Tiffany Aching books, we see both changes in the social structure that were made far earlier and then ignored (the female wizard Eskarina Smith in I shall Wear Midnight), and a double whammy in the death of Granny Weatherwax and appointment of Gregory as the new witch for her old area in The Shepard’s Crown. In the three waves, we go from stasis, to active defence of the status quo, to challenging and changing it.

Obviously this isn’t a perfect model. While I think the switch between waves one and two is fairly clear, as I noted above waves two and three are far more fuzzy in their boundary. Most notably, while I said that The Truth was the first major wave three book, between it and Monstrous Regiment and Going Postal, we have the second wave’s last hurrah; Nightwatch

Nightwatch is entirely build around the idea that nothing changes. Carcer’s actions threaten to change history, and Vimes has to put it back, while on the other side of the thematic coin, the revolution that the past characters, including young Vimes, are fighting for explicitly just results in more of the same, putting Mad Lord Snapchase in charge.

Except that…even here, we know that this is not true. Vetinari is in charge of Ankh Morpork in the modern day. Vimes has risen through the ranks to become the commander of the watch and a lord himself, a far cry from his humble, improvished beginnings.

The world will change, and sometimes those changes must be fought, but often we need to fight for those changes ourselves.