Can a ship exit jump space inside 100 diameters?
- Thread starter magmagmag
- Start date
There was an article on Jumpspace in an old 'Journal of the Travellers Aid Society' magazine that said that a ship 'precipitates' out of jumpspace at the 100 diameter limit. A ship attempting to exit jumpspace in the center of a planet would arrive at the 100 diameter jump limit instead.
That is the rule that I use, as Referee you are free to decide how it works in YOUR game.
That is the rule that I use, as Referee you are free to decide how it works in YOUR game.
IMTU, the *closest* you can exit Jump to any mass is 100 diameters. You can exit farther away (the outer system, for instance) but if you try to exit at 50 diameters, you get bumped out of jump at 100d.
So the short answer, IMTU, is no; and I think most Traveller universes agree on this. But as atpollard says, it's your game!
So the short answer, IMTU, is no; and I think most Traveller universes agree on this. But as atpollard says, it's your game!
no.
yes, but the ship then exits at 100 diameters, from the descriptions probably with a 2d mishap.
O
Odegra
Guest
You can jump OUT from a system within 100 diameters, but you seriously increase your chance for a misjump.
But you can't jump IN to a system and arrive closer than 100 diameters.
But you can't jump IN to a system and arrive closer than 100 diameters.
far-trader
SOC-14 10K
In MegaTraveller no you cannot jump closer than 100d to a world. Check the Starship Operating Procedures flowcharts of the Imperial Encyclopedia if you have that (of see below):
From MegaTraveller "Imperial Encyclopedia" copyright 1987 GDW:
I'm not sure if Marc Miller's Jumpspace article was the seed of this weed* but it didn't appear in the rules before that bit above.
It is Not in the MT Referee's Manual.
It is Not specifically defined in a sidebar mention in the the MT Player's Manual ("Ships are naturally precipitated out of jumpspace before they get too deep into a gravity field.").
Given the vagueness of the rule ("about 100 diameters") and the sidebar note ("before they get too deep into a gravity field") I allow that yes you can jump closer than 100 diameters, but it's not safe to do so.
And finally it is Not the rule in Classic Traveller (except perhaps in mentions outside the rule books).
*I call it a weed because it causes nothing but problems in my opinion.
From MegaTraveller "Imperial Encyclopedia" copyright 1987 GDW:
Some side notes and observations:
I'm not sure if Marc Miller's Jumpspace article was the seed of this weed* but it didn't appear in the rules before that bit above.
It is Not in the MT Referee's Manual.
It is Not specifically defined in a sidebar mention in the the MT Player's Manual ("Ships are naturally precipitated out of jumpspace before they get too deep into a gravity field.").
Given the vagueness of the rule ("about 100 diameters") and the sidebar note ("before they get too deep into a gravity field") I allow that yes you can jump closer than 100 diameters, but it's not safe to do so.
And finally it is Not the rule in Classic Traveller (except perhaps in mentions outside the rule books).
*I call it a weed because it causes nothing but problems in my opinion.
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I always liked the rule about 100 diameters, as it was the zone for lots of adventuring to happen. To emerge back into N-Space from JumpSpace, one needed a minimum of 100 diamters. Flight plans, jump tapes all facilated a sound jump but never guaranteed it. Only the military IMTU can jump with any accuracy (and even then)...when the players led a squadron of the Imperial Navy to rout some pirates...they found themselves very alone in the thick of battle before calvary came marching down on top of everyone.
I too remember a work (not sure which one) saying that you would get "bumped" out of dump space when entered a gravity well within 100 diameters of a body.
To roleplay this, it would probably feel something like your car striking something. It could be a "fender bender" or a more serious accident. Structural damage (among other things) is a likely outcome.
To roleplay this, it would probably feel something like your car striking something. It could be a "fender bender" or a more serious accident. Structural damage (among other things) is a likely outcome.
I'd, personally, treat it as a safety cut out based on the object's mass shadow in jump space. If jump space echoes real space, and gets shadows from objects in real space, then the jump drives are built with a safety limiter in them, that limiter is set to drop a ship to real space when it encounters a certain mass/gravity, that mass/gravity level tends to be encountered at about 100 diametres out from the planet, since the gravity and mass echo would fade at a near constant rate over distance, which can explain the amount of variance.
Now, you probably could rig a drive to bypass the limit, or make an interdictor ship that would magnify its mass shadow to the level that an unmodified drive's safety would cut in. The former would be an illegal mod, and would risk drive damage at least, possibly ship destruction, the latter would require a large ship with gravity projectors (tractor beam variants)
Now, you probably could rig a drive to bypass the limit, or make an interdictor ship that would magnify its mass shadow to the level that an unmodified drive's safety would cut in. The former would be an illegal mod, and would risk drive damage at least, possibly ship destruction, the latter would require a large ship with gravity projectors (tractor beam variants)
Peter Schutze
SOC-12
>about 100 diameters
I've always taken this to relate to the body's relative gravity .... so 100 diametres X density being the approximate real limit and people generally taking it as just 100.
in most cases its just a bit of a safety margin that never hurt anyone. after all bodies of interest (the 'mainworld') are likely to have a density very close to 1
I've always taken this to relate to the body's relative gravity .... so 100 diametres X density being the approximate real limit and people generally taking it as just 100.
in most cases its just a bit of a safety margin that never hurt anyone. after all bodies of interest (the 'mainworld') are likely to have a density very close to 1
There's an official writeup on Jumpspace by Marc W Miller in JTAS #24, that more or less takes you through the entire phenomenon, including coming out of jump.
I believe the answer is "no". My own take on it, is that there is a gravity threshold the drive/ship detects and fail-safe's the ship out of jump.
As for using it for a single plot gimmick or story, then it might work, if the GM approves.
Much thanks for your Traveller artwork !
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This is how I play it too.
IMTU masses in real space do NOT map onto jumpspace except at the real space / jumpspace interface. If they did then you would have ships routinely popping out of jumpspace in otherwise empty hexes and be lost.
The reason you can enter jumpspace within 100D but always exit atleast 100D is because the entry point is anchored by the jump drives creating the jump, but the exit point has no anchor (its whereever you aim for but it'll 'slid off' of difficult areas).
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