I have no idea what these "guilds" are! I have just got myst on my itouch and cannot get the other versions so ive jus watched youtube walkthroughs. what are the guilds?

he had an obsession with the number five?? why??

You see the D'ni sign for five everywhere in Riven. I think that was because he considered it to be his best age so far.

It wasn't that he was obsessed with that number or that it had some special meaning -- Gehn did not name his ages, but instead gave them numbers in the order they were written; Riven was his fifth age, thus the book has the number five on it, and you see that number throughout the age.

I have been cataloging the "natural" elements of this Age for nearly thirty years now, yet still I continue to find evidence of the D'ni's preoccupation with Five. As a boy, it was very clear to me that the number five had a special significance to the D'ni society -- from the ancient heraldic emblems of the ruling elite to the humble homes of the commoners, it was ubiquitous. Its presence here is obviously a direct reflection of the minds that designed the texts that I used to compose this Age -- further proof that through their Art the D'ni Masters were indeed creating the marvelous worlds they wrote, and not, as many have mistakenly thought, merely building links to preexisting worlds.

While most of my constructions have been based on D'ni designs, I see now that the ones that I have imbued with the power of Five are clearly the most beautiful, the most perfect. and, I believe, the most structurally sound.

I am still attempting to determine how the D'ni color symbology reflects this superior design principle. Although superficially it is based on a six color system, I am convinced that there has to be a deeper connection to Five. I will continue to investigate.