Kevin Siembieda (born April 2, 1956) is an American artist, writer, designer, and publisher of role-playing games, as well as being the founder and president of Palladium Books.
Palladium Books, founded in southeast Michigan, claims to be the first to implement a role-playing system intended to work for all genres and to introduce the perfect-bound trade paperback format to the RPG industry.
Some of the role-playing games Siembieda helped produce include Teenage Mutant Ninja Turtles & Other Strangeness (1985), Robotech RPG (1986), After The Bomb (1986), and Rifts (1990).
Siembieda is also an artist, best known for occasionally illustrating Palladium Books' products. In 1978, he started the now-defunct Megaton Publications in Detroit, publishing a digest style title called A+ Plus and several other titles. He also contributed art and cartography to several early Judges Guild products (for both their Traveller and Dungeons & Dragons lines).
While this is called the Game Master Guide, I think the note on the spine calling it a Mega-Sourcebook is a lot more accurate. There is a bit of basic GM advice here, and it's pretty good, going over some of the biggest pitfalls for new GMs and discussing how to create epic campaigns. However, in general this is a lot more like the original Dungeon Master's Guide by Gary Gygax than any modern book on how to run a game. It's filled with rules mechanics and short, sometimes odd essays on why certain things work the way they do. The book begins with, basically, errata, something that made sense in 2001 when this was first published. There are clarifications of combat rules and how strength works for different kinds of characters. I do appreciate this stuff, even if most of it has been integrated into the Ultimate Edition of Rifts. Most of the book is compilations of various resources from the 30 or so sourcebooks that had been published by this point. There's a list of skills, of psychic powers, of weapons from across Rifts Earth, and abbreviated stats for power armor, mecha, and other vehicles. I can accept the need for brevity with the latter, since this is mostly meant to be a quick reference and stick to an acceptable length, so it's not possible to reprint all the details of every piece of tech. For this reason, stuff from the Dimension books is largely missing as well, and magic gets its own sourcebook I plan to read at some point. A lot of the reading wasn't super exciting, and I honestly skimmed many of the stat blocks, but I will say that the skills and fluff about guns got me interested in Rifts Australia and Underseas, where I hadn't known much about them before. There are indices for character classes and monsters, a giant table of XP values, and then the book is rounded out with a mini-atlas of the game setting. This last is a bit overly focused on North America for my tastes, but in general this feels like it accomplishes what it sets out to do: compile the most essential material for actually playing a game of Rifts so the GM can carry this and the core book without needing a massive pile of other supplements. Yes, the way the Ultimate Edition of Rifts relies on the existence of this book a bit too much is annoying, but I can't blame this one since it came first, and coming from D&D I'm kinda used to needing a player's, GM's, and monster book anyway. This is pretty much an essential for any Rifts game, and even if it isn't the most exciting reading for the whole 352 pages (second only to Rifts Ultimate for longest Palladium book, by the way) it's still a great resource and well worth getting.