Diana Wynne Jones knows the world of high fantasy backward, upside down and sideways, as revealed in entries like this:
SCURVY: Despite a diet consisting entirely of STEW and WAYBREAD, supplemented only by the occasional FISH, you will not suffer from this or any other deficiency disease. It is possible that, while on the Tour, you absorb vitamin C through the pores of your skin.
She mercilessly skewers not just the tropes of the genre but also the writing, pointing out OMTs (Official Management Terms) throughout, eg galley overseers will be brutal, monastery libraries will smell mustily of old books, and Runes of Power will glow in the air.
It's all very funny, but I was mortified to realise how many boxes I had ticked in my own forays into fantasy. To name a few, I included LEATHERY-WINGED AVIANS, a TALENTED GIRL who SAVES THE WORLD with MUSIC, MIND-SPEECH, an OLD RUINED CITY which is also an ANCIENT ENGINEERING PROJECT, PIRATES, an OTHER CONTINENT, and a TEMPLE with ornate pillars (OMT) and an elaborately tiled floor. Oh dear!
Highly recommended. However, if I'd read this before I embarked on the Chanters of Tremaris, I don't think I would have finished one volume, let alone four 'brochures', as Wynne Jones calls them. I would have died of shame!