[crossfire] Proposal for better in-game information: client-side "player books"

[Raphaël Quinet]

Here is a quick summary of what was discussed a few hours ago on IRC.
These are basically some additions and clarifications to what was
posted here.  Eventually, this information should be summarized and
added to the wiki (dev_todo) and of course this should materialize as
real code...

* In order to explain why the readable items disappear after being
  read, it may be better to think about the "player books" as binders:
  the player finds some useful pages and stores them in her binder in
  order to carry them around easily.

* A player who has collected a lot of information could get additional
  "player books" (binders) to organize this information.  Another idea
  would be that each player starts with predefined binders, one for
  each type of information: one for monsters, one for religions, one
  for alchemy (or each sub-type: smithery, woodsman, ...) and so on.

* It may be better to replace the current random books by scrolls or
  "scraped book pages".  The information contained in the random books
  would usually fit on a single page anyway.

* Spell books are magic items.  This could explain why they disappear
  after being read.

* Besides the non-random books used in some maps, we could still have
  a few random books.  These would contain many pages and would be
  both (very) rare and (very) valuable.  Their value would depend on
  their number of pages.

* To explain the scattering of pages throughout the game: complete
  books are hard to find.  In most cases, individual pages have been
  ripped out of the books by those who found the information
  interesting.

* Since the server keeps track of what the player knows (contents of
  the "player book"), it is possible to only give litteracy exp for
  new information.

* Although the players would never drop any pages from their binder
  (unbinding pages would be impossible), those who have the writing
  skill (pen) and sufficient experience could copy the information
  into new scrolls or books and re-sell the result.

* As an added twist, the information copied from the books might not
  always be accurate.  Depending on the player's writing experience
  compared to the number of pages of the book from which the data is
  copied, some errors could be introduced at random.  In the copy, the
  description of an Ogre could be mixed with that of an Orc, for
  example. Or even worse: mixing up some spells and creating an
  incorrect copy that would result in a mana explosion when used.  The
  player would not even know that she is selling or giving away some
  garbled information.

These writing errors and their side-effects may not be easy to
implement: if the server keeps track of what each player knows (maybe
using a list of <type><id><part> for each character as described in my
first message) then we have to find a way to allow these errors.  The
server must remember what kind of erroneous information the player
has.  It must also allow the player who got some incorrect information
to replace it by a correct version if it is found somewhere.  But on
the other hand, the player who wrote it should not be able to tell the
difference (otherwise it would be trivial to check it by trying to
read what has just been written).  This is a bit tricky...

-Raphaël