Jumping in too close to the planet

[Richard Saunders]

Hello Gentles.
I have always allowed jumps from inside 100d bothways with the rule that for every diameter short of the 100 you are it's a 1% missjump chance, the calamity you suffer if you missjump is the difference between what you roled and what you needed to suceed, so if you did come out 100feet in the air the resultant bang would probably destroy the city as the reactor fuel and power plant went critical. And the role is for each end where you wish to enter or exit neerer than 100d.
If the result was a missjump then the distances where on the tactical map not strategic map, so you could end up tumbling toward the planet with no power.

 

[flykiller]

I didnt really want him to kill everyone, but I couldnt come up with what I thought was a decent enough answer as to why you couldnt.

say what you want. books 2 and 5 say nothing about it.

I always just say that jump is gravitic in nature. when a ship jumps from within a gravity well it gives the ship an extra push out, and when a ship jumps into a gravity well it reacts against the drives and damages them.

 

[womble]

The problem with 'arrive deep in a G-well and explode' isn't so much mechanical as meta-gamey. If an arriving-and-detonating ship could zorch a city from parsecs away, then it'd've been used as a weapon and space defenses would be unable to do anything to stop such bombardment. Of course the variability in time-in-jump would mean that hitting exactly the right city would be difficult, since the target is usually rotating...

Having the G-well dump you out of J-space at 100D (maybe with a random +/- 1-10%) is a nice safety cut off that avoids the ref having to deal with the issue.

 

[Andrew Boulton]

"Or have I totally misunderstood jumpspace lo this many years?"

[whimper]

No, no, please, I can't face the jump mask/jump shadow thread again...please, mummy, make it go away...

 

[rancke]

Originally posted by Shade1970:
I'm still not clear as to why you couldnt though.

No particular reason. It's just the way jump drive happens to work.

Do we mean to say that large objects will pull you from jumpspace?

Yes. Marc Miller wrote a detailed article about how jump works in one of the ltst print JTASses (#23?). If you have a subscription to JTAS Online[*], you can read it here:

http://jtas.sjgames.com/login/article.cgi?214

[*] And if you don't, you should seriously consider getting one. It's cheap and gives you access to tons of crunchy bits.

If so, this means I've totally misunderstood jumpspace. I thought you were entering a different " dimension " ( universe, reality, what have you ) and the drive put you in and it took you out. So I'm not really clear as to why you couldnt come out anywhere you wanted...horrible consequences or not.

It's just the way jump drive works.


Hans

 

[Andrew Boulton]

NONONO! It's starting again!

[runs screaming from the room]

 

[mike wightman]

Maybe this time no one will bite
CT was just a set of rules to make up your own universe after all.
If Shade 1970 has managed to avoid the various jumpspace articles and threads and keeps doing things his way there's no problem with that.
There are lots of ways to explain how the jump drive works (and it keeps changing in Traveller canon anyway)...
<slaps self - Oh no... almost got dragged into it again... must resist...>

 

[far-trader]

There there Andrew, it was just all a bad bad dream.

 

[Shade1970]

>>Do we mean to say that large objects will pull >>you from jumpspace?
>Yes. Marc Miller wrote a detailed article about >how jump works in one of the ltst print JTASses >(#23?). If you have a subscription to JTAS >Online[*], you can read it here:

>http://jtas.sjgames.com/login/article.cgi?214

Ok, thanks. Thats really what I was looking for, not so much the deep discussion of jump mechanics that at least one of you fears enough to leave the room screaming.

>[*] And if you don't, you should seriously >consider getting one. It's cheap and gives you >access to tons of crunchy bits.

Actually, I do have one and havent been overly impressed by it. Between that and the rancorous discussion groups...well, lets just say there's a reason I posted my question here and not there. I dont want to make this a big criticism topic either.

John

 

[Shade1970]

BTW,

For those of you keeping score, I have e-mailed the player that caused the question to be brought up in the first place and told him that the 100d limit would pull him out of J-space and he'd have to hatch a different terrorist plot.

John

 

[Whipsnade]

Mr. Shade,

Just to nip one question in the bud that I know will arise in the future...

A vessel precipitates out where it hits the 100D limit and not when it hits the 100D limit.

Let me explain further. Your player will read all the responses you recieved here and immediately pick up on the word when in the sentence You precipitate out when you hit the 100D limit. He'll then think "I have found a way to jump faster than the usual 168 hours!" and rush to explain it to you.

The trick will be to plot a jump that purposely intersects a 100D limit. You plot a two parsec hop for instance that just so happens to 'bump' into a world one parsec away. You push the button, drop into the hole, and - VOILA - emerge at the world one parsec away in only half the time it would normally take.

Sorry, but your player's future great idea won't work. Jump lasts 168 hours plus or minus 10 percent, period. Misjumps may last longer or shorter, but jumps last 168 hours.

So, you precipitate out where you contact the 100D limit and not when you contact that limit. Bump into that world one parsec away while jumping two parsecs and you'll still emerge 168 hours after you hit the button.

Just how the limit effects the vessel is up to you and how you view jump travel. The limit could be 'reflective' and the vessel 'bounces' off on a different jump vector. The limit could be 'sticky' and the vessel stays 'stuck' to the point where it intersected the limit and is dragged along with it. The limit could also be 'smooth' and the vessel will 'slide' along it as the limit moves and finally clears the jump course.

It's up to you, but you can't use 100D percipitation to short circuit the 168 hour time duration.

Have fun.


Sincerely,
Larsen

 

[clementk]

Originally posted by daryen:
The real question is what happens if you enter jump a few hundred feet above the city.

I played in a Ursula session during a raid on a planet. One of the raider ships was damaged and tried to jump inside the planet's atmosphere above a city while the pc group was on the ground below running for their lives. Needless to say it was similar to a nuclear bomb in total initial destruction and damage pattern and between the initial blast, shockwave, afteraffects I learned Asu (my pc) could wind surf*! The crater was several km in diameter and damaged a downport and part of a city IIRC. Fortunately Asu managed to fly through a upper story window of a solid enough building and duck down. Sometimes being short and light helps. ^_^

So *NOT* recommended especially if your ship is damaged. One of the best sessions I've played in on Ursula ever and that's saying a lot.

Casey

* it would've been kind've fun in better circumstance as it was I was having Wizard of Oz flashbacks

 

[vutpakdi]

I imagine that the 100D limit also works with regards to stars. So, for a planet orbiting close enough to a giant type star, the ship would precipitate out because of the star's 100D limit rather than the planet's 100D limit.

Ron

 

[Whipsnade]

Ron Vutpakdi wrote: "I imagine that the 100D limit also works with regards to stars."


Mr. Vutpakdi,

Congratulations, sir! You've just independently re-invented the idea of jump masking and re-discovered the desirability of LASH freight operations.

Please to refer to GURPS: Far Trader for any further information.

By the way, there is a system in the Spinward Marches whose mainworld is so 'deep' in the star's 100D jump limit that a one-gee journey from world to limit is measured in days.


Sincerely,
Larsen

 

[Malenfant]

IIRC Antares' jump limit is at about 1000 AU from the star (that's about 25 times the radius of Pluto's orbit in our solar system)!

For the Antares Project on JTAS (which when last I looked had been put on permanent hold), we figured that the mainworld would be orbiting a brown dwarf outside the star's 1000 AU limit, but there was still a significant chance of a ship intersecting Antares' 100D limit on its way in or out (especially if going to/coming from a direction toward the supergiant) despite that.

 

[Vargas]

Originally posted by Larsen E. Whipsnade:

The trick will be to plot a jump that purposely intersects a 100D limit. You plot a two parsec hop for instance that just so happens to 'bump' into a world one parsec away. You push the button, drop into the hole, and - VOILA - emerge at the world one parsec away in only half the time it would normally take.

Wouldn't work IMTU; precipitation due to gravity only happens near the end of Jump. Any other time you can fly through a star or bounce too close to a supernova.

 

[rancke]

Originally posted by Vargas:
</font><blockquote>quote:</font><hr />Originally posted by Larsen E. Whipsnade:

The trick will be to plot a jump that purposely intersects a 100D limit. You plot a two parsec hop for instance that just so happens to 'bump' into a world one parsec away. You push the button, drop into the hole, and - VOILA - emerge at the world one parsec away in only half the time it would normally take.

Wouldn't work IMTU;</font>[/QUOTE]And as Larsen takes pains to explain just below the bit you qoute, it won't work in the OTU either, though the explanation why is murkier than IYTU.

...precipitation due to gravity only happens near the end of Jump. Any other time you can fly through a star or bounce too close to a supernova.

Yes, that's the way it worked at first, but Marc Miller has since made it abundantly clear that intervening objects (of sufficient size) do interfere, hence the introduction of jump masking in addition to jump shadowing.


Hans

 

[Andrew Boulton]

[crawls under table, assumes fetal position, and begins humming "Daisy, Daisy"...]

 

[Malenfant]

Again, it's worth reminding people that the probability of a ship's path between two stars actually intersecting the 100D limit of any obstacle big enough to cause it to drop out of jumpspace is extremely low.

The Pioneer and Voyager spacecraft passed through the asteroid belt in the 1970s and didn't smack into an asteroid, after all. Even Oort cloud objects are separated by dozens of AU and are comparatively tiny, so a ship can easily fly right through it without going near any of them.

 

[far-trader]

Well said Malenfant. Also even a star-system in a seemingly direct line between two others is extremely unlikely to actually be in the way. It will in all likelyhood be well out of the way in the plane perpendicular to the jump line. I don't believe every plotted system is in the exact center of its hex and on the exact same plane (though that gets into other issues of 2d vs 3d and are the maps representitive or specific).

Anyway, unless the referee has a burning need to drop the characters out of Jump there should be no chance of any random early (in distance, not time) jump precipitation due to interferance once in jump. Before entering yes, a big enough ship might be able to cut off your jump line, and you have to get clear enough of things like planets and stars too. Even then I don't think it should be an automatic, more like an increased chance of misjump imo.

Sorry Andrew

Sometimes this stuff has to be said I guess.