The Greyhawk grognard have started a very good discussion about a very good question. What use are art in an adventure module anyway?
If you ever have tried to create a sellable game book of your own, you have probably been thinking about it. It's easy to find cheap writing, and if you can't find anyone doing it for you it's easy to imagine your own scribblings to be good enough. For some reason most of us balk at the idea of having our drawing shown to all the world, though.
While that is a sign that most people have no idea how to write good and proper English, it also say something about our perception of art. Line art drawn by a ball-point pen isn't good enough for most of us. I remember when I, almost twenty five years ago, first laid eyes on the 1st ed AD&D PHB. I thought it looked terrible! Later I learned to like it better and these days I have two copies in my shelf.
So, what use are a piece of art in a adventure module? Apart from the aesthetic reasons there are a few. A page layed out without any art at all are going to be a bit tougher to read. Less text, and less text in a big chunk, is easier to get a grip on. Apart from that, which game book do I have that contained good art that made sense?
Take D3 - Vault of the Drow, for example. It has 9 pieces of art. Of those two are of vital importance, since they introduce two new monster which are not even described except for the illustration! One of those make the monster look like a fat guy dressed in a monster suit, though. But, what use are the others? Well, one is depicting a naked woman, which probably meant the difference between a sold module or not for those young men who thumbed through this booklet at the game store back in 1978.
Then there are pieces like the one on page ten of D3. For those who haven't read the purple prose in high gygaxian I feel sad. The "fungi growths in golden and red ochres, vermillion, russets, citron, and aquamarine shades ... The rock walls of the Vault appear hazy and insubstantial in the wine-colored light, more like mist thah solid walls. The place is indeed a dark fairyland." Looking at the black and white picture on page ten, I can see those scintillating colours and the mystery lining the vault is plain for all to see. It's the best thing Gary ever wrote, as far as I'm concerned. The illustration and text here enter a total harmony and complement each other.
So what use are art in an adventure module? Hard to answer, but it's a good question. I can only answer well by example of when it's done well, and manages to include an example of when it's terrible. If I manage to publish something, I hope I can achieve something powerful once, and that's it. The rest is text, baby.