13. There has been much discussion about this, but UU wizards do reluctantly concede that this is the historical state of affairs. Rincewind certainly challenged Coin with said sock, and as a result Coin ceased his troublesome reign (admittedly because being challenged by the most ineffective wizard in the world with such a primitive weapon amused him, caught his imagination and persuaded him to defy the power of his father). There are other ways to defeat someone than by bashing their head in with a brick (although this does remain the means of choice in many of Ankh-Morpork's shadier streets).

14. Originally a Sharp Stick was installed, but extensive tests found that few things were worse than a poke in the eye with it.

15. Although octarine is the most important colour as far as wizards are concerned, it is not one that lends itself well to paint pigmentation. It quickly fades in sunlight and, in extreme cases, walks away.

16. A very popular degree and comparatively easy to obtain; a bit like sociology. Most wizards manage to get a B.F. after their name, to the quiet amus.e.m.e.nt of the citizenry in general.

17. This one is a bit of a puzzler.

18. At the time of the floor being relaid that is. This is done every few decades, during which time many of the constellations will have changed or been renamed.

19. It's amazing how much can change in twenty years! Now, of course, there are numerous Terry Pratchett fan clubs, entire conventions dedicated to the Discworld and alt.fan.pratchett has been superseded by other chat groups, fan websites, Facebook pages, Twitter accounts (and whatever else has no doubt emerged between writing and publishing this!) 20. Updated from the 1994 edition.

Also by Terry Pratchett.

THE CARPET PEOPLE THE DARK SIDE OF THE SUN STRATA.

THE UNADULTERATED CAT (with Gray Jolliffe) GOOD OMENS (with Neil Gaiman).

NATION THE LONG EARTH (with Stephen Baxter) DODGER.

A BLINK OF THE SCREEN: COLLECTED SHORT FICTION.

The Bromeliad.

TRUCKERS DIGGERS WINGS.

Johnny Maxwell.

ONLY YOU CAN SAVE MANKIND.

JOHNNY AND THE DEAD JOHNNY AND THE BOMB.

The Discworld series THE COLOUR OF MAGIC THE LIGHT FANTASTIC.

EQUAL RITES MORT SOURCERY WYRD SISTERS PYRAMIDS.

GUARDS! GUARDS! ERIC (with Josh Kirby) MOVING PICTURES REAPER MAN WITCHES ABROAD SMALL G.o.dS LORDS AND LADIES.

MEN AT ARMS SOUL MUSIC INTERESTING TIMES MASKERADE FEET OF CLAY.

HOGFATHER JINGO THE LAST CONTINENT CARPE JUGULUM.

THE FIFTH ELEPHANT THE TRUTH THE THIEF OF TIME THE LAST HERO.

NIGHT WATCH MONSTROUS REGIMENT GOING POSTAL.

THUD! MAKING MONEY UNSEEN ACADEMICALS SNUFF.

Discworld (children's) THE AMAZING MAURICE AND HIS EDUCATED RODENTS WEE FREE MEN.

A HATFUL OF SKY WINTERSMITH I SHALL WEAR MIDNIGHT.

Discworld collaborations MORT: A DISCWORLD BIG COMIC (with Graham Higgins) GUARDS! GUARDS! (with Graham Higgins) THE PRATCHETT PORTFOLIO (with Paul Kidby) THE STREETS OF ANKH-MORPORK (with Stephen Briggs) THE DISCWORLD MAPP (with Stephen Briggs) A TOURIST GUIDE TO LANCRE: A DISCWORLD MAPP (with Stephen Briggs and Paul Kidby) DEATH'S DOMAIN (with Paul Kidby) THE COMPLEAT ANKH-MORPORK (with The Discworld Emporium) NANNY OGG'S COOKBOOK.

THE DISCWORLD'S UNSEEN UNIVERSITY DIARY 1998 (with Stephen Briggs and Paul Kidby) THE DISCWORLD'S ANKH-MORPORK CITY WATCH DIARY 1999 (with Stephen Briggs and Paul Kidby) THE DISCWORLD a.s.sa.s.sINS' GUILD DIARY 2000 (with Stephen Briggs and Paul Kidby) THE DISCWORLD FOOLS' GUILD YEARBOOK AND DIARY 2001 (with Stephen Briggs and Paul Kidby) THE DISCWORLD THIEVES' GUILD YEARBOOK AND DIARY 2002 (with Stephen Briggs and Paul Kidby) THE DISCWORLD (REFORMED) VAMPYRE'S DIARY 2003 (with Stephen Briggs and Paul Kidby) THE DISCWORLD ALMANAK (with Bernard Pearson and Paul Kidby) THE ANKH-MORPORK POST OFFICE HANDBOOK & DIARY 2007 (with Stephen Briggs and Paul Kidby) LU-TZE'S YEARBOOK OF ENLIGHTENMENT 2008 (with Stephen Briggs and Paul Kidby) THE WIT AND WISDOM OF DISCWORLD (compiled by Stephen Briggs) THE ILl.u.s.tRATED ERIC.

THE ART OF DISCWORLD (with Paul Kidby).

WHERE'S MY COW? (with Melvyn Grant).

MISS FELICITY BEEDLE'S THE WORLD OF POO (with Bernard and Isobel Pearson).

end.