HARRY Potter stuff is everywhere. Broomsticks, spell casters, magic mirrors, pencil cases, pyjamas, fire-breathing dragons and Bertie Bott's Every Flavoured Beans. Never before, it seems, has so much merchandise been devoted to one film. Entire sections of supermarkets and toy shops are devoted to Harry Potter. The choices are mind-boggling - and that's even before the film has opened.

So where do you begin?

First, the good news: many of these toys and games are genuinely different. They are not merely old themes re-worked with Harry Potter characters superimposed over Pokemon or Toy Story or Thomas the Tank Engine or whatever last year's craze was. They have a neat originality about them that lives up to the Harry Potter name.

And some are easy to judge - the Lego Sets, for instance, are a good blend of the long lasting appeal of Lego

and the fun of Harry Potter. You can't go wrong. Sets start at £4.99 for a Sorting Hat to Hogwarts Castle at £79.99 with nine others in between.

But what about the games? Tricky to judge these just by looking at the box. So we swooped down into Diagon Alley to find some of the most widely available games, and got our little team of wizards to test them out - well, there have to be some perks for having journalists as parents.

DEFINITELY MAGIC

QUIDDITCH CHAPTER GAME £9.99

VERY neat this - a game that unfolds from a book. And also, more importantly, folds neatly back into it so the pieces shouldn't get lost. This is Quidditch played on two levels. Rules are easy to grasp but it's one of those games where you can not only try and win yourself _but you can also be nasty and ruthless and prevent your opponent from winning. So while you're aiming for the Golden Snitch you can bludger your opponent off the board onto the lower level. In the right (or wrong ) hands, this is Quidditch as a blood sport.

Officially for eight-year-olds and over, this is good for all ages and easily grasped - even by granny with a glass of wine in her hand. Great fun. Will be a classic.

MYSTERY AT HOGWARTS £19.99

THIS looked quite complicated until we realised that it is actually a variation on Cluedo. Only what you have to find out is which professor saw which baddie putting which spell on which victim. Tricky. But worth it. Secret passages, ghosts.

Takes a while to master the rules - so probably rightly judged at eight-year-olds and upwards - but so much more fun than Colonel Mustard in the library with the lead piping.

MAGIC MIRROR JIGSAW £5.99

A 200-piece jigsaw sounds easy enough, but not this one. Yes, you have a picture on the package. Unfortunately the picture is square, but the jigsaw is circular, so the pieces are distorted. The only way to see them properly is in the curved mirror - that also doubles as a holder for the pieces.

The problem with this is the shiny box isn't ideal as a mirror, especially when it had got a bit bashed. But it was still a great idea. The jigsaw was tricky but not impossible and it was fun watching it emerge in reflection. For six-year-olds upwards.

FAIRLY MAGIC

QUIDDITCH CARD GAME £6.99

Quite complicated this - cards for Chasers and Keepers and Beaters, plus quaffles and bludgers and, of course, the Golden Snitch. If your little wizards have the patience to master it, it could turn out to be quite a good game. But you probably need a few hours of a power cut for them to be bothered to make the effort.

NOT VERY MAGIC AT ALL

CASTING STONES GAME £9.99, plus any number of booster packs at £2.99.

This is a very nice-looking game - counters are thrown onto a circular playing board that doubles up as a nice little pouch bag which holds the pieces. Each counter represents a spell, potion or charm and the game is really a version of Scissors, Paper and Stone - only more complicated.

Also more expensive as the more stones you have, the better you do - hence the compulsion to buy booster packs. Not so much a collecting game as a getting out there and spending more money game. Not to be encouraged.

PROFESSOR SNAPE'S POTION CLASS £29.99

LOOKS intriguing, an edible activity set in which children can brew magic, drinkable potions.

There's a self-stirring wand, which is quite fun, and a special cauldron that makes potions bubble and boil - the equivalent of blowing a straw into a drink, and a vessel that pours the mixture into cups. But once you've assembled it, made a sticky mess or two, there's nothing else to do with it. Boring. Also there is no list of ingredients anywhere - so those highly coloured drinks could be dripping with E numbers, likely to turn your angels into hyperactive monsters. You have been warned.

BEST BUY

If they haven't got the books, get them those, or treat them to audio tapes of the whole lot as read by Stephen Fry - they will keep them quiet and feed their imaginations at the same time.