YMMV / Sourcery

• Anticlimax Boss: The Archchancellor's hat. It takes over the Grand Vizier and a big show is made of his ability to effortlessly annihilate even the sourcery-empowered wizards. He's engaging in open warfare with Coin... and then Carding essentially trips him (although that's only made possible because he was distracted by The Luggage in the first place), causing him to lose control of the magic he was using and annihilate himself. Considering how much effort went into stealing the hat, transporting the hat, recovering the hat, etc, you'd think that more time would go into stopping him when it's revealed that he's Knight Templar willing to end the rule of sourcery by force, even if it destroys the world in the process.
• Complete Monster: Ipslore the Red, having been thrown out of Unseen University for taking a wife and having children, vowed revenge, his obsession causing him to discard his previous love. Siring his eighth son Coin, a sourcerer—a wizard capable of creating magic granting them near unlimited power—merely as a tool for revenge, Ipslore cheated Death by binding his spirit to Coin's staff, threatening to kill the boy should Death remove him. Over ten years Ipslore molded Coin into an utterly dependent killing servant, punishing even the slightest defiance with Electric Torture. Using Coin to murder several wizards to gain him control of the university, as well as killing one for being kind to his young child, Ipslore sets the university loose against the city, turning Lord Vetinari into a lizard and letting the wizards terrorize the helpless population of Ankh-Morpork. Under Ipslore's rule, anyone who attempts to interfere is killed regardless of their inability to stop Coin. Letting his hubris overtake him and still hungry for more power, Ipslore has Coin freeze the Discworld pantheon, now desiring to rule the entire disc, completely uncaring his actions could bring about the collapse of reality itself from the Ice Giants arising or the excess magic attracting the Things from the Dungeon Dimensions.
• Hilarious in Hindsight:
  • The Archchancellor's Hat can now seem like a dark parody of Hogwarts' Sorting Hat, even though this book came first.
  • "He [Lord Vetinari] didn't administer a reign of terror, just the occasional light shower". That sounds a lot funnier now – after Charles Dance played Vetinari in the Going Postal adaptation and then went on to portray another Memetic Badass character whose The Dreaded status is closely associated with a rain-related pun (and a song centred around it).
• Inferred Holocaust: A huge number of implied fatalities, though there is debate as to whether the Reset Button covers these or not. One could say that a reason why the wizards change from amoral Vancians to magical Oxonians is that Coin/Ipslore killed all of the former.
• Magnificent Bastard: Conina the Hairdresser is a stunningly beautiful barbarian heroine whose hardened instincts prevent a simple life as a hair stylist. An impossibly skilled thief who once pickpocketed jewels the victim had swallowed for safekeeping, her theft of the Archchancellor's hat prevents Coin the Sourcerer from gaining its powers. Threatening the cowardly wizard Rincewind into helping her find it a suitable host, she uses her street smarts and weaponized usage of a comb and scissors to lead a journey around the world. During the great magical war in the climax, she outplays an unhelpful genie to force its aid and steals the Four Horsemen's horses to help save the Discworld from an apocalyptic fate.
• Moral Event Horizon: Ipslore takes a step over the line through his torture of Coin alone, but then really goes over-the-top with his subsequent takeover of the university and Ankh-Morpork, crushing anyone that has the misfortune of being nearby.
• Nightmare Fuel:
  • After a few books of being generally harmless to the outside world (if far from it towards their colleagues), this book shows just what would happen if the then-amoral wizards got their hands on a major source of power - they waste no time terrorising the nonmagical Ankh-Morporkians, killing several and scaring even more away. To make matters worse, while future Archchancellor Ridcully genuinely had nothing to do with the incident, it's implied most of the senior faculty of later books (bar Ponder, who was too young, and the Librarian who actively fought against the Sourcerer) were involved in some capacity, though they at least have the decency to feel ashamed about it and downplay their roles (which was implied to be minor at most).
  • The fact that by the end, the world is about to end because of both the Ice Giants and the previously-seen Things from the Dungeon Dimensions.
  • Abrim after he puts on the Archchancellor's Hat. He looks and moves like a corpse. He probably wishes he were one.
• The Woobie: Poor Coin's entire reason for being is to serve as his father's world-conquerer-by-proxy, and really wants nothing more than to be a good kid. Just try not to feel sorry for him when Ipslore encourages him.
  • Don't forget Rincewind. He has it bad in this one, spending a large portion of his POV angsting about the situation he gets into, how important being a wizard is to him (despite the fact that he's completely incompetent) and by the end getting stuck in the Dungeon Dimensions until his next book.