Terry Pratchett 
Interesting Times 
(Discworld Novel 17)

”There is a curse. They say: may you live in interesting times . . .”

This is the worst thing you can wish on a citizen of Discworld. Especially for the magically challenged Rincewind, who has already had far too much excitement in his life.
Unfortunately, the unlucky wizard always seems to end up in the middle of, well, absolutely everything. So when a request for a ”Great Wizzard” arrives from the faraway Counterweight Continent, it”s obviously Rincewind who”s sent. For one thing, he”s the only one who spells wizard that way.
Once again Rincewind is thrown headfirst into a dangerous adventure. For the oldest empire on the Disc is in turmoil and Chaos is building. And, for some reason, someone believes Rincewind will have a vital role in the coming war . . .
”Pratchett is a comic genius” Daily Express
”Funny, delightfully inventive, and refuses to lie down in its genre” Observer

Interesting Times is the fifth book in the Wizards series, but you can read the Discworld novels in any order.