Pulled from Jim Shooter's blog:
Why did you write Secret Wars?
Marvel’s writers at the time, some of the best in the business, were, to a person, very possessive about the characters they were writing. To some extent, that was a good thing, indicating a love for the characters that generally showed in their work. It also led to some intense rivalries and bitter arguments regarding crossovers and guest appearances.
For instance, once, writer “A,” who shall remain nameless, wanted Doctor Doom to “guest-villain” in the series he wrote. I okayed it, over the snarling objections of writer “B,” who wrote the series in which Doom usually appeared. I would not allow the Marvel Universe to be divided into fiefdoms. But then, writer “B” wrote a story “proving” that the Doom seen in writer “A’s” series was a robot, the intimation being that the real Doctor Doom wouldn’t behave so stupidly. Somehow, writer “B’s” editor didn’t realize what he was up to, and let it slip past. Writer “A” was furious…etc.
Allowing any one of the writers to handle pretty much everyone else’s characters in Secret Wars, contemplated to be the biggest, most continuity-intensive crossover ever done, would have led to bloodshed in the hallowed halls.
So, I wrote it. As Editor in Chief, by definition, I was the company’s designated Keeper of the Franchises, and the ordained Absolute Authority on the characters -- all part of the job, at least back then. The writers could (and did) argue with me, and on some occasions talked me into their point of view regarding what Thor, Spider-Man or the X-Men would do or say in a given situation. But, ultimately, it was my call. That made things a little easier. And less bloody. And, because I had the best overview of what was going on in all the titles, working closely with the line editors and writers I was able to keep the continuity tight. And, with their help, I think we managed to work in the things Mattel asked for in ways that made sense and enhanced the story.
Why did you pick Mike Zeck as the artist for Secret Wars?
Mike was available and I thought he was capable. Mike did great work on Master of Kung-Fu. SW presented new challenges -- designing alien things and doing vast-scope action. The vast-scope action was new territory for Mike -- MOKF and his other, previous work had been single characters, all up close and personal -- so I actually thumbnailed some of the issues for him. The design stuff he did brilliantly. Witness the black Spider-Man costume.