The GM should decide what the world is like in my view, including whether or not there are spellbooks on that bookshelf a PC randomly decided to search.
Yes, I'm aware of that. I hold a different view.
Why the heck would the player have anything to do with authoring that bit of fiction, and how would them not authoring suddenly be a railroad?
I haven't said that the player would author that bit of fiction.
The player authors the action declaration, "I search the upper floor of Evard's tower for spellbooks". Now, this happened in BW, so the rule for the GM is "say 'yes' or roll the dice". The GM is expected to say "yes" if nothing is at stake (where what is at stake is relative to the players' evinced concerns for their PCs). In this case, there clearly was something at stake: Aramina, Thurgon's travelling companion, had brought them to the tower to find spellbooks, and that was why Thurgon was searching for them. So the GM called for a check (my guess would be Scavenging, though I can't recall for certain anymore).
If the check succeeds, then intent and task are realised: Thurgon finds spellbooks for Aramina.
If the check fails - which it did - then Thurgon's intent is not realised. What he actually found were letters, that appeared to reveal that his beloved mother Xanthippe is, in fact, the daughter of the evil wizard Evard.
The player (me) did not author the fiction, but plah was not a railroad: the stakes and consequences are not being established solely by the GM. They are being authored having regard to my (the players') evinced concerns for my PC - his Beliefs (about Aramina and Xanthippe), his Relationships (to Aramina and Xanthippe), etc. To use the language of AW/DW, this is an example of the GM being a fan of the characters.
Now, when you (
@Micah Sweet) say that play should not revolve around the PCs, I take you to mean that play should not play out in the fashion I've just described, and that if the GM has made a decision about what is in the tower (spellbooks, letters, whatever) then that's that. The players can learn about what the GM has decided is there; and the players can choose which "there" to poke around in; but the GM will not author fiction about what is there in response to the players' evinced concerns for their PCs.
The sort of play that I have described in the previous paragraph is what I regard as a railroad. (Again, I repeat this caveat: if essentially we're playing a wargame, like Isle of Dread or White Plume Mountain, then the whole logic of things is different, and the characters are just player pawns. That's not a railroad, but it's not really a game with characters at all in any meaningful sense. It shares a basic similarity of form with the sort of RPGing I enjoy, but in its details is a completely different activity.)
EDIT:
Well now I'm struggling to see what's excluded by this definition. I got the impression it wasn't just the player specifically making declarations beyond their character's direct actions, but perhaps I'm mistaken.
This post provides an illustration. There are many more that you could see in my numerous actual play threads on these boards.
