Firstly I will point out there are two versions of the game: Fantasy Flight and the Original
The FAQ states:
Example: The Event cost at Speak Friend and Enter requires the players to discard a Friendship and Joker symbol. Frodo volunteers since he can discard any two white Hobbit cards to pay for the cost.
Frodo's ability is the same ...
A similar question has been asked at BGG:
The collected wisdom is:
You can buy Gandalf cards with either the gold or the silver, or a combination of the two. Any time you need to discard runes, you can discard either or both.
The silver runes are gained through the spaces on the board, and you always gain one rune per space. The gold runes are stacked face-...
Yes, the players can interrupt the nazgul card and avoid its main effects.
First you must resolve the symbol in the upper left of the Nazgul card. After that, because the main text of the Nazgul card treated as if an event tile were revealed, it can be interrupted by anything that can interrupt event tiles, such as putting on the Ring, Gandalf, etc.
As Erik P. said it is not necessary to know the story to play the game. I would add that it can be a good way to be introduced to the Lord of the Rings world.
I think the games goes quite deep into the story, but not in a way that gives an advantage to who has read the books. There are 4 maps: Moria, Helm's Deep, shelob's lair and Mordor (plus Bree and ...