James Hofmann wrote:

>  It seems like a really simple idea now, yet so few games try to do something
>  like this with their editing tools. They always make you do everything within
>  the editor, with the "test" mode only for testing. I wonder why that is?

I think it depends a lot on the nature of the game
how much the editing and playing engines can benefit
by sharing code and user interface.

In one of my current WIPs, editing and playing are
quite heavily intertwined, being done more or less
by slightly different modes of the same program.
It works there because the kinds of manipulations
that the creator and the player can perform on the
world are very similar. (It's a game where you
have a kit of parts to play with, a little like
The Incredible Machine, and the main difference
between authoring and playing lies in which
parts you're allowed to move around.)

In other kinds of games, the editing and playing
environments can be very different, and there
mightn't be much gained from trying to integrate
them -- it might even be more difficult than
keeping them separate.

Another reason might be if the game were
developed by a team, with one person or group
working on the editor and another on the playing
engine, without much interaction between them.
I can imagine that sort of thing happening a
lot in the development of commercial games.

Also I'm not sure how far you could go in making
a general-purpose editor along these lines. In
my experience, the capabilities required of a
game editor tend to be very specific to the
game in question, and with an integrated
player/editor, it's even more so.

It's an interesting idea, though, and I'll be
interested in any more thoughts anyone has.
I'm always on the lookout for neat new tools
for making games...

--
Greg