[net.games.frp] fizicks in d&d

tgm@ukc.UUCP (T.Murphy) (04/15/85)

>net.games.frp.physics is a great idea!   I'm a technical type, and i always
>enjoy a game more when there is a semi-plausible physical explanation.
>This also helps figure out tricky questions, such as mana depletion.

I agree wholeheartedly with Mr. Kahn. To me, a system of physics
governing magic is essential. The way I see magic is as a subset
of an overall system of physics. In no way inconsistent with the
normal laws of physics. This brings up arguments like the following:

Argument:
	If you are invisible then all light passes through
	you so you aren't seen. But if this is so, then there
	is no light reaching your retina so you shouldn't
	be able to see.
Counter argument:
	The invisibility spell is illusion/phantasm not
	alteration. So you are in effect invisible because
	Those who are affected refuse to acknowelege your
	presence (like a S.E.P. field). This is why it is
	negated when you attack (How can you ignore someone
	who is attacking you?).Discovery:
	So if you are invisible and you stand in front of
	a small object (a secret door, say) then your
	oponents should not be able to see it since they
	`refuse' to look at you.
Answer:
	Try it and find out!

Physics is still physics; the heat has to go somewhere after a fireball.
You don't end up with such idiotic things like gunpowder not
working for unexplained reasons (cf. Greyhawk by the Great Ghod
Gygax). I prefer my players to know the how and why of the world
they are living in so they can make intelegent decisions instead
of stumbling around in the dark.

I admire Niven's fantasy stories for their adhearence to the
laws they set up and I get many of my ideas from him. Magic in
my world is driven by taping the power flow from the positive
material plane to the negative material plane. (I see these not
as being the source of good and evil but as the source of light
and darkness, no mysticism) Normal space has a certain permability
to this power flow. Thus effectively causing your regions of
high and low mana. An apprentice learns you to create micro-
scopic gates to both planes and to chanel the power flow from
one to the other (the notation black and white holes has just
occured to me). The higher in level the larger the gate one can
control. So a fireball is a split-second gate to the positive
material plane 1mm cubed. This is effected by opening your gates
and shutting the negative of just before the positive. Cold is
a bit more tricky. You have to open a gate to the negative slightly
larger that the positive and create a siphon effect. Sorry to
be so technical but I find this type of discussion a large part
of the enjoyment I get out of D&D. Of course those who run a
hacking campaign or a `lets keep the players in the dark so I
can fiddle it as I want' or a `I make it up as I go along' will
probably find this /realistic/ viewpoint objectionable.
Just to Theoretical Physics and Magic go hand in hand.

	{decvax,seismo}!mcvax!uck!tcdmath!jaymin
Joe Jaquinta; c/o D.U. Maths Society; 39.16 Trinity College Dublin; Ireland
--------------------
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Send mail to the above address.

jeff@alberta.UUCP (Curt J. Sampson) (04/21/85)

In article <5047@ukc.UUCP> tgm@ukc.UUCP (T.Murphy) writes:
>Argument:
>	If you are invisible then all light passes through
>	you so you aren't seen. But if this is so, then there
>	is no light reaching your retina so you shouldn't
>	be able to see.
>Counter argument:
>	The invisibility spell is illusion/phantasm not
>	alteration. So you are in effect invisible because
>	Those who are affected refuse to acknowelege your
>	presence (like a S.E.P. field). This is why it is
>	negated when you attack (How can you ignore someone
>	who is attacking you?).Discovery:
>	So if you are invisible and you stand in front of
>	a small object (a secret door, say) then your
>	oponents should not be able to see it since they
>	`refuse' to look at you.

Actually, the invisibility spell in my games creates a "blind spot" for
anybody looking at that person.  You don't see anything there, but you don't
know you are missing anything.  You know the door is there because you can
see parts of the door around the person, or you saw it before the person
moved there.  You mind will fill in the details that you are not "seeing."
--
	Curt Sampson		ihnp4!alberta!jeff

"There is a theory which states that if every anyone discovers exactly what
 the Usenet is for and why it is here, it will instantly disappear and be
 replaced by somehing even more bizarre and inexplicable.

"There is another theory which states that this has already happened."

euren@ttds.UUCP (Leif Euren) (04/26/85)

Quote Curt J. Sampson:
:
>Actually, the invisibility spell in my games creates a "blind spot" for
>anybody looking at that person.  You don't see anything there, but you don't
>know you are missing anything.  You know the door is there because you can
>see parts of the door around the person, or you saw it before the person
>moved there.  You mind will fill in the details that you are not "seeing."

This will also explain why intelligent, high-levelers will understand that
there is an invisible present, as stated in DMG. A very good explanation, me
thinks.
						Leif Euren

js2j@mhuxt.UUCP (sonntag) (05/01/85)

> >Actually, the invisibility spell in my games creates a "blind spot" for
> >anybody looking at that person.  You don't see anything there, but you don't
> >know you are missing anything.  You know the door is there because you can
> >see parts of the door around the person, or you saw it before the person
> >moved there.  You mind will fill in the details that you are not "seeing."
> 
> This will also explain why intelligent, high-levelers will understand that
> there is an invisible present, as stated in DMG. A very good explanation, me
> thinks.
> 						Leif Euren
    Does this mean that creatures with magic resistance also get a chance to
see someone who is invisible?  With this interpretation of invisibility, it
seems as though the spell affects the minds of the people who look, so magic
resistance should apply.  Personally, I run invisibility as though it really
makes people invisible.  It's more reasonable to think that a second level
spell with a duration like invisibility works that way than to think that it
affects everyone who looks in your direction from any range with no saving
throw.
-- 
Jeff Sonntag
ihnp4!mhuxt!js2j
    "Did you ever wonder ... why you're supposed to drive on a
     parkway and park on a driveway?"

mike@wuphys.UUCP (Mike Jones) (05/03/85)

You want fizics, you got it.  I use invisability as an actual bending
(more like light piping) of the light around the invisible object (or
person).  This avoids making invisability a mental attack of the "you
don't see me" type.  The reason I don't like this is that most such
mental influences have saving throws.  Invisability dosn't have a
saving throw, so it isn't like that. (Clerical sanctuary is exactly
like that, and it does have a saving throw).

The objection is that if all the light is bent around the person then
the person can't see.  The key word is all.  How much light do we need
to see?  From my handy Physics Vade Mecum (handbook) we find that
unobscured sunlight is ~10^5 lux (lm m^-2).  A quarter moon at 30
degrees above the horizon (still adequate visability) is about 10^-2
lux.  So the human (not to mention elven or dwarf) eye is capable of
seeing over a range of 10 million in ilumination. So all we need to
allow is an inefficiency of 1 part in 10 million and the person inside
can see.  We can do better than that if we need to.  One in 10 million
is allowing a hole in the invisability the size of the pupil (all the
rest can be 100.0000% effiecient), since we are bending light anyway,
its perfectly reasonable to focus light in from a slightly larger area,
so all we need to see is a patch of perhaps a few square cm which is
99.9999999% effiencent and we can see fine (in full daylight).  This
has to be scaled for lower light, but in full darkness invisability
dosen't have to work very hard anyway.  The detect invisable chance at
high levels is based on slight ineffencies which mean the exact
direction of bending is not perfect or perhaps diffraction effects at
the invisability/ normal space interface.  Sorry this got so long
winded.

Mike Jones Physics Dept. Washington University St. Louis
ihnp4!wuphys!mike