Take one farm boy - select your farm boy wisely, allowing for boyish good looks, charm, mop of hair and the kind of physique which suggests they look after themselves, without having won any junior bodybuilding awards.

Put them, to nobody's surprise, on a farm. Preferably a farm in the middle of nowhere, relatively isolated, and certainly not anywhere near a big city. Give them some form of family figure to look over them but subtly suggest that there has been family trauma for the farm boy to deal with.

Make the farm boy live in tempestuous times, nothing like as peaceful as they once were. Create a rather large and menacing empire ruled by a dark, twisted leader, one who administers power using equally malevolent underlings with special powers.

To this add the farm boy's future: a resistance movement, hiding out in unlikely locations, waiting patiently for the leader their myths and legends tell them will come (cue: farm boy).

So what do you end up with? Yes, you do indeed end up with Star Wars. But you also end up with Eragon, the new fantasy film of Lord of the Rings aspirations. Universally panned it has been, were we to talk like Yoda for a moment. Reasons are many and varied, but they focus on: poor dialogue, bad acting, lack of a decent plot, and complete inconsistency with the apparently rather good book of same name.

That seems to be the real bugbear for many. As with Harry Potter and any other epic that could be eleven feature films in its own right before you even reach the second in the series, Eragon the film is, I'm told, nothing like Eragon the book. Some people dare to suggest the follow-up film (and there'll be one, alright - we saw the evil dragon at the end and it looked like it had some fire-breathing to do) will be nothing at all like the follow-up book because the plot has been destroyed. That will certainly make things interesting for whoever has to do the screenplay.

The joy of all this is that, having not read the book, I didn't give a monkey's that the film doesn't represent it very well. Some of the acting could have been better, and the dialogue was all quite hammy and unrealistic, but then there is a dragon involved from start to finish. This rather renders cries of "the dialogue was unrealistic" a little superfluous. If you have a dragon in your film, you're entitled to depart reality and it's our own fault for wanting the impossibility that is a realistic film with dragons in it.

My personal success-o-meter for any film is: how long before the film finished did I start pining for it to end? Blessed as I am with the kind of attention span that would render me King Among Goldfish, but only just, I tend to start eyeballing the watch even in the best of films. If it's a bad film, keeping it mercifully short will earn you enough brownie points to restore it to mediocrity. The Eragon credits were rolling before I'd even given thought to the fact the film might end, so for all its faults it kept me ticking contentedly over in the cheap seats (alright, luxury seats) throughout.

The dragon in it is very good, by the way - voiced very well and, as we have come to expect these days, it looks suitably as though it actually exists. However I did feel the evil forces of the empire demonstrated an incapability bordering on the farcical in their inability to find this dragon. Bear in mind that there are henchmen everywhere out to find the boy with the dragon, the only dragon in existence apart from the king's. Now, this dragon is big. And it's flying around a lot. You know it's not the king's dragon, and you know there are no other dragons. Somehow boy and dragon make good their escape and the henchmen end up a good few days behind! It had been circling in the bloody sky for days!

Sum total: not a classic by any means, but not the 100 minutes of torture many people proclaim - unless you've read the book, in which case it may well be the cinematic equivalent of having your soul eaten by badgers. And yes, it's the plot of Star Wars, but with dragons.