🚀 go-pugleaf

You want to do a study of object-oriented Adventure Games?  Well, step 1,
familiarize yourself with what's out there already.  TADS is a popular
system.  It's written by Mike Roberts and is shareware: you can FTP it
from msdos.archive.umich.edu, file /pub/msdos/games/adventure/tads.zip
(there are also Macintosh and Atari versions on the same machine, probably
under /pub/mac/... and /pub/atari/... though I'm not sure of the paths.)
TADS is similar to C++ in appearance.  However, to really pick up much about
the system, you'll have to register and get the big manual with lots
of sample source code and tools.  It's quite cheap and I recommend it.
You can get registration information by sending e-mail to Mike Roberts
at 73737.417@compuserve.com, or by looking in the shareware TADS package.

There are several other Adventure Development Systems, all more-or-less
object oriented.  ALAN is a popular one; you get the source code to the
compiler for that.  ADVSYS and AGT are also good.  I believe these are
all LISP-like in appearance.  I don't know how you'd get them, though;
perhaps someone else can help.

As for TADS, which I'm more familiar with, I don't know how well it
matches your criteria but it certainly can be extended.  What you call
"NPCs" (other Actors) are not quite as general as you want: they do run
independently, but Adventure games are mostly structured around your
command and responses to it.  If you want "smart" Actors you'll have to
write some AI-like code.  I'm sure Dave Baggett at the MIT AI lab, the
author of the classic "Unnkuulian Unventure II" Adventure game, will be
full of suggestions.

By the way, I'm not sure I follow what you mean about Sierra games.  Sierra
On-Line hasn't made an adventure game since the days of TimeZone and
The Wizard And The Princess, have they?  Graphics would certainly be
nice but any sort of non-static graphics is hard to do in any Adventure
development system I've ever seen -- they're not oriented towards that
sort of stuff.

If you really want lots of discussion of this, you should post your note
in REC.ARTS.INT-FICTION.  That is the newsgroup for people writing Adventure
games.  You should get more advice than you'll ever need.

- David Librik
librik@cory.Berkeley.edu

"You are standing before a roughly-hewn doorway in the rock.  Mist curls out
of the blackness beyond.  The arch above is carved with the words 'WRITING
YOUR OWN ADVENTURE SYSTEM.'  A small sign next to the door reads 'ABANDON
ALL HOPE YE WHO ENTER HERE.'"