Re: Ok, major problem: staircases are major headaches!

On Thu, Jun 01, 2006 at 12:58:49PM +0100, David Shepheard wrote:
> >From: Johannes Werner <joe@???-?????.de>
> >On Wed, May 31, 2006 at 07:48:30PM +0100, David Shepheard wrote:
> >> <snip>...I think that they introduced a monster that could
> >> create extra gravity as a special attack. So that does imply that 
> >increased
> >> gravity might exist. Gravity is actually something that the SJ3e 
> >conversion
> >> crew need to think about at some point.
> >
> >What was the effect of that special attack? More like a "reverse
> >gravity"? (Un?)fortunately, our DM did not know/use this creature, so I
> >do not know it...
> 
> I found a 3.0e conversion of the Gravislayer by Flits3 and Marc Doolan on 
> Shattered Fractine:
> http://www.shatteredfractine.com/critters/monsters/gravislayer.html

Sweet. So it does not really change the gravity in a way we would have
to recalculate completely...

> I also found Aaron Siddall's conversion of a humanoid race (I'd forgotten 
> about) called the Grav:
> http://www.shatteredfractine.com/critters/monsters/grav.html
> 
> The gravislayer was from MC7 and the grav was from MC9.

Thanks for enlightening me!

> >> If gravity that is different to 1G can exist then what happens if a ship
> >> from a 2G planet goes into wildspace? Do they keep their double gravity 
> >or
> >> do they suddenly drop down to 1G?
> >
> >Hm. One _could_ argue that a ship can be considered too small to have
> >"gravity" of 2g, resulting in the problems described below... especially
> >if you land on a low gravity world, would the world's gravity still
> >suppress the ship's gravity plane?
> 
> I'd agree. But, the point I was trying to make was that you need to examine 
> everything if you start to vary gravity. I think it shouldn't be included 
> in the core SJ rules.

Yes. I think this quite concludes the discussion on variation of gravity
with "just don't do it in the core rules, it is too messy / confusing /
unnecccessarry"...

> >> If variations in gravity do exist then would we need to adjust strength,
> >> speed or jumping statistics for people travelling onto or off of 2G 
> >worlds?
> >>
> >> On a 2G world you and your equipment weigh double the normal weight.
> >> Falling speed (including terminal velocity) can be double.
> >
> >No, terminal velocity would be limited by air friction. You could argue
> >that it would be even _smaller_ than on a 1g world, since the air is
> >"thicker".
> 
> You are right about air friction, but wrong about air being thicker. Venus 
> has a lighter gravity than Earth, but a much greater air density. The two 
> are not necessarily related. More reason for *assuming* that gravity, air 
> density, terminal velocity and other similar things are universal in the 
> core rules and only adding variations in *later* add-on products.

Well, if the chemical composition of the atmosphere was exactly the
same, I would agree. But I believe that this discussion does not really
help the conversion of the core rules. 

> >> Falls cause
> >> double damage. Reaction times for falling would be halved.
> >
> >Hm. This would increase the DC of the tumble check...
> 
> But then someone would add a Gravity Adeptation feat: "You have spent time 
> on a high gravity world and can cope with blah, blah, etc, etc..."
>
> >> If you allow a
> >> planet with two-thirds G you are going to get some odd fractions when 
> >you
> >> do the mathematics (not to mention have a headache when a ship goes into
> >> the planets atmosphere and gravity decreases ).
> >>
> >> Another problem with gravity variations is that you suffer from the 
> >lowest
> >> common denomiator when you refresh your air envelope. Skim to a 2G world
> >> and your ship doubles in weight (but not mass). Logic suggests that your
> >> doubled weight would allow you to pick up double the amount of air.
> >> Unfortunately when you leave the world, your ships weight falls back to
> >> normal and the excess air would bleed off - you are no better off than 
> >if
> >> you skim air on a normal G world.
> >>
> >> (BTW: I'm not sure if the spelljamming helm works on weight or mass, but
> >> for arguments sake, I'll say it works on mass and you don't drop like a
> >> stone when your ships weight suddenly jumps above 50 tons.)
> >
> >Would make sense to me...
> 
> Actually, after doing a tiny bit of Googling to look for nautical terms it 
> looks like ships tons could be a measure of volume rather than a measure of 
> weight or mass:
> http://en.wikipedia.org/wiki/Ton#Units_of_volume
> "One freight ton or measurement ton is equal to...40 cubic feet."
> 
> I say "could" because Wikipedia also has a displacement ton and a 
> deadweight ton:
> http://en.wikipedia.org/wiki/Ton#Units_of_mass
> 
> "A displacement ton is...the mass of 35 cubic feet of water." and a 
> deadweight ton is the same as a long ton (2240 pounds). Either of these 
> types of tons may have been used by the original designers of Spelljammer. 
> (This might cause a mathmatical error to anyone trying to convert sailing 
> ships from other RPG products!)

Hm, wasn't there something in the core rules that one ton was equal to
(some amount) of (I don't remember)? But since this discussion has been
going on for a while (and keeps popping up in connection with ship
sizes), I don't really know. For a conversion of ships, I usually just
take a ship from the rulebooks that has more or less the same properties
and then just change it around a bit. This _can_ be a quick process (but
does not have to). To accelerate discussions, one of my old gaming
groups had a sand glass (1 minute?) that would be turned around by the
person being sick of the discussions. Time stops -> discussion stop.
Yes, it _did_ apply to players _and_ GM...

> >> Now lets assume you go and skim air on a 1/2 G world. Your ship suddenly
> >> weighs half as much as before. The extra air would presumably bleed off
> >> leaving you with 1/2 bar of air pressure (500 millibars). When you go 
> >back
> >> into space your ship would return to its original weight, but would only
> >> have half the standard amount of air.
> >>
> >> Of course you could decide that air pressure is not related to gravity 
> >and
> >> avoid this issue. I'd personally prefer to stick to a 1G (1000 millibar)
> >> universe, but if people really want to create higher G planets I would
> >> suggest that:
> >> 1) It is done in as an optional add-on rather than as part of the core
> >> rules and
> >
> >I strongly agree, it would get too messy to stay self consistent,
> >logical and consistent with the core rues (I am afraid)
> >
> >> 2) Gravity is kept to multiples of 1G (whole numbers/integers) to make 
> >the
> >> mathematics of things easier to work out.
> >
> >Hm, so no "low gravity" moon, where you can jump around like a crazy
> >kangaroo and accidently leave the air envelope and the influence of the
> >gravitational plane?
> 
> I could be wrong on this one. I'll leave it to the people who design the 
> gravity variation product.
> 
> By the way, this product could include a "Gravspace" crystal sphere 
> featuring the homeworld of the grav, new monsters with gravity manipulation 
> abilities (including variations on the gravislayer - baby gravislayers, 
> perhaps), gravity related spells and a gravity clerical domain. I'd also 
> suggest making several monsters have telekinetic powers as they can counter 
> the grav and gravislayer abilities.

Well it would be telekinetic in the sense of a very localised "change
gravity" spell(-like ability). Sounds good! I'd hate to get lost in that
sphere...

> >> If you want an idea of how this transition might feel then try going to
> >> your local swimming baths.
> >>
> >> Get in the water next to the edge of the pool and push yourself under 
> >the
> >> water. You should feel an upwards force from bouancy at this point. Then
> >> pull yourself upwards and try to pop up as high as possible.
> >>
> >> If you are very strong you will be able to hop onto the edge of the 
> >pool,
> >> but even if you are weak you will realise that boyancy will stop gravity
> >> from pulling you too deep underwater when you fall back in.
> >
> >The damping in your example is just much higher, in air you would
> >continue to oscillate... Actually I did not think about forward
> >momentum, see below... :-(
> 
> Like I was saying - you need to think about this a *lot* to get it to all 
> work together.
> 
> >> I can imagine that people doing "Adam's trick" would need a little bit 
> >of
> >> practise to avoid either:
> >> 1) Overdoing it and jumping up into the air on the reverse deck or
> >> 2) Underdoing it and falling back into the gravity plane.
> >>
> >> People that overdid it would possibly risk headbutting the ceiling, but
> >> most people would probably go through with their hands in the air to 
> >avoid
> >> this.
> >
> >Ouch. Or you could wear some sort of protective gear. Or nail a mattress
> >to the ceiling.
> 
> Or you could curve a handrail around the path a person would follow. Or you 
> could use attach a rope to the edge of the hole and hold onto the end to 
> stop you overdoing things.
> 
> >> People that underdid it would end up bobbing up and down in the hole and
> >> would probably have to grab the sides to stop and then crawl out.
> >
> >Would look quite embarrassing...
> >
> >> Getting this wrong would be a common problem for groundlings and you 
> >could
> >> make anyone without BtM's *free* Spacefarer feet roll a dexterity check
> >> whenever they cross a gravity plane.
> >
> >Well, I am not really sure if you would not learn this trick rather
> >quickly (or continue suffering the consequences). I'd say that with the
> >feat you would not have to roll (except maybe in stressfull situations like
> >combat).
> 
> Thinking about this some more I'd be tempted to say that anyone can get 
> through the gravity plane with no trouble as a full round action. But add 
> that people can get through quicker (probably as a move equivelent action) 
> by making a tumble check (perhaps with a DC of 20).
>
> As a person passing through the gravity plane does not know what is on the 
> other side, I'd argue that they provoke an attack of opportunity from 
> anyone standing at the spot where they appear.

Don't know. The person did not really see you coming, so this might
require a readiead action.

> >> >> --- Adam Miller <night_druid3000@?????.com> wrote:
> >> >>
> >> >> > Generally, here's how I see it: there's a big hole
> >> >> > in
> >> >> > the middle of the deck.  Fall face forward into the
> >> >> > hole, through the gravity plane, and your momentum
> >> >> > takes you back into a standing position on the other
> >> >> > side of the gravity plane.  Simple.  Doesn't work
> >> >> > all
> >> >> > the time (centaurs, for example), but for
> >> >> > experienced
> >> >> > space hands, shouldn't be a problem.
> >>
> >> Don't forget that Dracons and Centaurs are both found in wildspace (and
> >> Dracons are a PC race according to the Complete Spacefarer). They must 
> >have
> >> a way to get round the fact that their front legs and back legs would
> >> temporarily be in opposing gravity planes.
> >>
> >> Here is an idea. Perhaps you could use some sort of special hinge to fix 
> >a
> >> plank to the edge of a hole. A centaur (or similar creature) could walk 
> >out
> >> to the end of the plank and their weight would make it swing downwards. 
> >Get
> >> the hinge right and the plank could swing 180 degrees to leave them
> >> standing upside down on the underside of the floor (or to put it another
> >> way the floor of the reverse gravity deck). If the plank extended an 
> >equal
> >> distance from the hinges on both sides it could work a bit like a seesaw
> >> that only had one person on it.
> >
> >This would not work unless you nail them creature in question to the
> >plank, a plan that you are not going to make any friends with... I also
> >would have to think about where a centaur's center of mass is. It's a
> >bit late now and I have not slept enough (or had enough tea, only
> >~3 litres), so I might not get the right picture at the moment. I just
> >realised that this might also cause problems with "Static's Method" (was
> >it him?). We did not account for the forward momentum of the center of
> >mass of the person / creature in question.... so the process would be
> >like this (everything described from an outside position):
> >- you approach the hole (lets assume from left)
> >- you tumble through the hole (face forward)
> >- conservation of momentum and angular momentum will turn you around and
> >  move you further to the right
> >- conservation of energy (together with the changed gravitational pull)
> >  would make sure you land on the other side of the deck
> >- you would end up on the right handside of the hole, facing left,
> >  walking (or running, depends on initial velocity) to the right side,
> >  which now is _backwards_ for you.
> >If you overdo it, you bounce to the ceiling, if you underdo it, you
> >maybe start to oscillate but then hurt head and/or back when hitting the
> >right side of the hole.
> >This method does not look too nice for me. Actually, I am afraid that
> >even experienced space hands would have problems with that...
> >Excuse me for nitpicking...
> 
> Maybe a platform that slowly does a forward flip while you pull on 
> handholds would be better for centaurs, dracons and people with cargo.

Sure. Or just a sling of rope through which to put one of your feet. It
this was done in a sensible way, you could just swing youreslf around,
you would also not risk to bounce onto the ceiling (just hurt your foot
/ leg quite a bit).

> >> There are two problems with a device like this:
> >> 1) The "landing area/departure area" would be a dangerous place to 
> >stand.
> >> Suddenly you would find a dracon or centaur swinging down onto your
> >> position and
> >> 2) As this device is a flip-flop device it might be "the wrong way up" 
> >when
> >> you wanted to get onto it.
> >>
> >> To avoid the second problem you would probably need something like a 
> >rope
> >> on both ends to pull the device back to your side of the transition 
> >area.
> >> If this rope went through the deck to join to the other end it could
> >> perhaps have some sort of mechanism (similar to the devices that
> >> automatically close doors) to stop a centaur/dracon from slapping the 
> >deck
> >> too hard when they use a gravity flip-flopper (or whatever you want to 
> >call
> >> it).
> >
> >Hm. The question (as usually) is:
> >- would anyone care for such a "scientific" approach? My friends
> >  might...
> >- is this _really_ neccessary? I mean, this is a game. The mechanics do
> >  not have to be scientifically correct, in fact, many of them are not,
> >  and should not be. Just think of the gravitation...
> >Sorry for (maybe) creating more discussion and confusion, but these are
> >the problems I would encounter in 2/3 of my gaming groups...
> 
> I'd save the "scientific" approach for tinker gnome inventions and come up 
> with a simple explanation for everyone else. (The main thing is to make 
> sure that the deck plans for reverse gravity decks are done right - I'd do 
> them both ways up so that they could be turned over when you landed a ship 
> on a groundling world.)

Still, these questions would be asked by some people, even some gamers I
know. You just cannot forget your education completely. While this works
for dragons, magic and such, this does not work for basic effects, like
conservation laws... *shrugs*
Well, I'd say: rather make it simple and understandable and narative.
Too many rules and scientific considerations can kill a game.

Joe