Well, I'm currently working on background for fantasy universe, and I'm trying to go very in-depth to answer as many questions as I can--not to deluge the readers/players with, should it be in story/game format, but so that I have those answers should the need for them arise. Its especially kind of important because there's a crossover potential between various worlds, including a modern earth setting.

I'm a big fan of Tolkein, and one of the main reasons for that is because of the depth of history that can be glimpsed in the Hobbit and Lord of the Rings--you can just feel it. There's so much in his development of Middle Earth that never sees explanation in the main books, but it being there adds a richness to the world that I don't think you could ever really match by making stuff up on the spot just to suit your current plot development needs. And so, what i'm trying to ask myself is a bunch of questions that it might help to have answers to.

So, basically, i'm looking for any questions that you might sometimes ask yourself when reading fantasy novels that just don't seem to have any explanation than "It was convenient" or "magic!"
A few examples are:

Why is it that in fantasy novels set on other worlds, the dominant species is almost always 100% identical to earth humans?

Why do almost all fantasy worlds have versions of chess and court-based playing cards and other earth games?

Why does there always just so happen to be a Chosen One conveniently nearby when disaster is about to strike?

Why is the villian always trying to destroy the damn planet/solar system/galaxy/universe?

Aand.. How exactly does that airship stay in the air with just those few prop-blades?

Well, I'm currently working on background for fantasy universe, and I'm trying to go very in-depth to answer as many questions as I can--not to deluge the readers/players with, should it be in story/game format, but so that I have those answers should the need for them arise. Its especially kind of important because there's a crossover potential between various worlds, including a modern earth setting.

I'm a big fan of Tolkein, and one of the main reasons for that is because of the depth of history that can be glimpsed in the Hobbit and Lord of the Rings--you can just feel it. There's so much in his development of Middle Earth that never sees explanation in the main books, but it being there adds a richness to the world that I don't think you could ever really match by making stuff up on the spot just to suit your current plot development needs. And so, what i'm trying to ask myself is a bunch of questions that it might help to have answers to.

So, basically, i'm looking for any questions that you might sometimes ask yourself when reading fantasy novels that just don't seem to have any explanation than "It was convenient" or "magic!"
A few examples are:

Why is it that in fantasy novels set on other worlds, the dominant species is almost always 100% identical to earth humans?
The author has to sell books and an easy way for the reader to emotionally connect to the characters or plot is by making
them humans. Also using humans as a point of view to explore an alien world makes it easier than the other way around.

Why do almost all fantasy worlds have versions of chess and court-based playing cards and other earth games?
Authors are by definition nerds? Don't know

Why does there always just so happen to be a Chosen One conveniently nearby when disaster is about to strike?
Messiah effect in my opnion. It is deeply rooted in the human psyche that we as a race will be saved if something out of the impersonal universe or we ourselves causes a catastrophy. See Ragnarok and the God Baulder. Can't remember the other mythological references.

Why is the villian always trying to destroy the damn planet/solar system/galaxy/universe?
Because a villian who tries to raise taxes is not as scary.

Aand.. How exactly does that airship stay in the air with just those few prop-blades?
Some genious put helium in the hull surrounded by fire-proof wood?

What else can you guys add? These can be common cliches to even things that you've only seen once or twice. Basically, i'm just looking for questions to help me brainstorm and flesh out the laws of my universe as much as possible.

Thanks in advance!

A good book on writing is Stephen King's "On Writing." A good one on horror is "Dance Macabre."

A Song of Ice and Fire is a far better series than The Wheel of Time, and conveniently breaks most of the second posts conventions.

Um. I think there's been some misunderstanding. I'm not looking for answers. I understand the familiarity aspects and all that. What i'm looking for is questions that one might ask themselves while reading that authors don't bother to answer, even if to themselves, which is what i'm trying to do--answer those questions in my own universe's history and rules and such.

Trying to answer every possible question is not necessarily the best route to go, or you'll end up with a story where readers skip through pages of tedious explanations in order to get to the meat of the plot. A certain book, which shall remained unnamed, proved this point rather well when it turned every magical ritual into a ten page geometry lesson.

I'm a big fan of Tolkein, and one of the main reasons for that is because of the depth of history that can be glimpsed in the Hobbit and Lord of the Rings--you can just feel it. There's so much in his development of Middle Earth that never sees explanation in the main books, but it being there adds a richness to the world that I don't think you could ever really match by making stuff up on the spot just to suit your current plot development needs.

Only in bad books. Even Tolkien had Good folk who were devoid of compassion for evil. Like that guy in Hobbit who could change into a bear - I forgot his name. Mea maxima culpa.

A Song of Ice and Fire is a far better series than The Wheel of Time, and conveniently breaks most of the second posts conventions.

Read the Silmarillion, for starters.

I liked them both, to be honest, but the Song series was the only one that had me throwing up my hands, saying, "screw this!" because every time I found someone who it looked like I could root for (Tyrion, Jon, etc) they performed something that threw them into the dog house. Too confusing.

If nothing else, despite how bossy every single bloody woman in the WoT series was, it was a good set of books. Well written, a believable world, and the way things were going, it looked as if the Shadow was going to win regardless.

Read my original post, for starters. I mentioned it, if not by name, in reference to Tolkein's background works.

I'm sorry. I could have sworn you called the Wheel of Time series well-written and believable. I must have misread something in that sentence. Some of the books were entertaining, sure, but the series is far from the height of fantasy novels. You can only have women tug their braids, fold their arms, and yell at Matrim so many times before it gets a tad predictable and repetitive.

Also, you obviously didn't read far enough into a Song of Ice and Fire... but talking about what happens truly ruins the tension of a book that will kill off your favorite character and his or her entire family at the drop of a hat, so I'll refrain from saying any more than that. The Song series is also far from over - the new book, A Dance of Dragons, is on the horizon.