5 out of 5 stars. This is 128 pages of fact, history, speculation, multiple worldbuilding scenarios, and bibliography. Yes, a reasonably extensive bibliography in a game supplement. That’s what I appreciate about GURPS; their writers do the research, and it shows.
Two specific reasons I’d recommend this to aspiring writers. First and obviously, it’s a great sum-up of what we know about Plato’s Atlantis and its possible origins, and what people have speculated since, including the possibility of ancient stories passed down of the drowning of Doggerland in the North Sea about 6500-5900 BC. Second, if you’re trying to build your own fantastic world, whether urban fantasy, SF, or fantasy, you’re going to do what Phil Masters did here. You’re going to research all kinds of things that may or may not be related to your story, winnow it down to what fits, then put down the sources and build the world of your dreams. This book lets you get a feel for how someone else did it. It’s a roadmap you can follow, and when you’re trying to do something as utterly outrageous as dream up a whole world, a starting map helps.
Another plus is that because it is a gamebook, it’s meant to be used to give characters adventures. So you can look at scenarios that are supposed to be “game balanced” such that a group of heroes can win through and succeed… if they work together and don’t do anything too idiotically stupid. You could think of it as guideposts on how to do a satisfying story: not so easy it’s a walk in the park, not so hard that all but one of your heroes dies horribly by the end of the book. GURPS’ point system lets you compare monsters and characters across wildly divergent settings, and get a feel for, “do these characters have matching power levels, or is one side going to obliterate the other?”
Yes, this is crucial when writing crossover fanfics. But it also comes into play in series books, since you’re often introducing a new Evil of the Week in each succeeding book. Better to figure out if the new Lord Necromancer is going to crush your heroic Sir Knightley into a bloody smear before you’re a hundred pages into the rough and stuck, with visions of the readers screaming at you.
Back to Atlantis. This book covers magic and myths, archaeology and science, and the practical aspect of getting to a sunken land in the first place. It also proposes scenarios for Atlantis making contact with the outside world… or the other way around, with at least 3 different Atlantis versions based on various myths and fantastic fiction. I am amused by a bit on orichalcum in one of the more magical versions: “This is a fantasy setting; players who demand to know where it is on the periodic table should be ignored.” I could wish Stargate had taken that approach.
Note, this was originally published in 2001, so a paper copy might be hard to find. But if you want to poke worlds of watery destruction, it’s worth looking for.