Where to begin?
Originally posted by jatay3:
One of the disadvantages of jump is it is incomprehensible and inflexible. Therefore the number of adventures available are limited. Certainly little can be done that requires manuvering of the vessel.
I totally don't get this. Incomprehensible and inflexible in what ways?
The number of adventures is limited only by your imagination. The
TYPES of adventures are certainly limited, but they would be likewise limited for any changes made, they would just be
DIFFERENT TYPES of adventures.
Disadvantages are only what you call it if you can't make it work for you
Originally posted by jatay3:
I propose to make it reasonably common for the entry point to be several days out from the main port.
Certainly this can be easily done for YTU, and it may even work but...
There are a number of consequences you'll have to think about and figure out before jumping in. Pun not intended, but it's a good one

Bad sign though, I only get punny when I'm drinking or tired, and I'm not drinking, so more posts beyond this may have to wait for a nap
Let's see, some quick off the cuff problems...
If you move the jump point several days from the mainworld, all your jump traffic is going to be from the spaceport set up at the jump point. All in-system traffic will be non-jump transfers between the world(s) and the jump point spaceport. That
WILL happen in the standard Traveller trade systems. And if your PCs are the usual model with a starship they won't be going in-system. And you're back where you started, only worse...
This model also leads to another huge change in traveller trade. Merchies will no longer have a reason to spend a week on the mainworld. They'll come out of jump right at the spaceport (give or take a few thousand klicks), offload their cargo, load ready cargo, fuel up and be off, all within a day probably. So now instead of extending the time in normal space you've reduced it enormously. Unless you can invent a reason for them to have to go to the mainworld or hang out at the spaceport.
This will also hugely impact the bottom line of merchies. They'll be making enough money from just freight to get stinking rich, or at least break even on the payments. Even if they are paid per jump rather than per parsec. Heck the old Far-Trader might even be a money making proposition. Because instead of just 25 trips a year under the old 1 week in system and 1 week in jump model, it'll be 1 day in system and 1 week in jump. Something like doubling the revenue potential of every ship.
Originally posted by jatay3:
This provides some interesting thoughts.
Indeed it does, but you may not like some of them. And they all need to be thought out for unintended consequences. Discussion of them is certainly good...
Originally posted by jatay3:
...low-class starports in the outer rim of a system(and all the atmosphere of lonely obscurity that implies). There could also be competition between the main world starport which is closer to the market, and the rim starport which is often closer to the traffic.
I think the low class starports, and they will be simple spaceports in actuality, will be the ones farthest from the spaceport at the jump point. Look at any realworld examples. The big seaports are the ones where the boats can most easily navigate to, not the ones that are way up-river. Rivers that require shallow draft, slow speeds, icebreakers, channel pilots, waits for drawbridges, etc...
Manufacturing will set up at the starport or use boats (i.e. Truckers) to get the goods to the starport.
This is where the translation to slow big in-system spaceships (not starships) fits. And while a campaign could be built on this, a very good one in fact, it won't be the usual kind of Traveller game. I think it may be the one you want though, with pirates preying on slow ships in convoy with protection but days from real help.
Originally posted by jatay3:
...there could also be in navigational tables and almanacs lists of what time of year the most ideal jump can be reached(thus involving calculation of the loss of time in waiting as oppossed to the loss from entering system at a sub-optmal time).
A possibility, and one that appeals to me in ways. I even tried coming up with a simple way to model it long ago. What it will mean is something akin to seasonal trade to and between certain systems. So if PCs do go to a system in the off season they are unlikely to find much cargo or passengers to solicit, and if they are travelling on tickets and end up in such a system in the off season they may have a long wait on world before the next starship comes along.
Originally posted by jatay3:
The chief disadvantage of this is obvious-it means time in system becomes a more important factor to calculate, and changes the structure.
Disadvantage? I thought this was your goal, the raison-d'arte of the thread, the point
No question it does change the stucture, of just about everything
Originally posted by jatay3:
...what would be the problem that would cause this? A thought is the masking caused by outer planetary bodies.
Certainly one possibility but not supported by the rules or reality. You'd need an almost solid shell to do that. Something like this may exist, the Oort cloud could be used to make such a barrier. Trouble is it's way out there, and I mean waaaaaay out there. If it's a barrier you'll have ships making half parsec plus jumps to get there, navigate through it, and then jump on again.
This would be a very different Traveller universe. One with two types of starships. The in-system ones who go between the world(s) and the barrier, and ones that go between these "shells" and never see the systems they service.
The real Oort cloud is probably not dense enough to pose such a barrier but it could be for a slightly different type of jump mechaninc. One where any matter between the start and end point poses a serious hazard.
Originally posted by jatay3:
I do think more time-in-system is at least sometimes needed.
And if it's only needed sometimes there's no need to go and change things on a wholesale scale. Implement it in YTU on a case by case basis as needed for the story.
In this vein I've always thought asteroid systems might be taken to mean ones with no large worlds, just a whole mess of proto planet rocks, dust and gases in orbits around the star(s) and for safety you'd have to come in somewhere beyond the farthest orbit of debris to avoid hitting something one time in a million.
So the military, pirates, and desperate scoff-law PCs would jump into and out of the middle of the mess if needed but the law for merchies would be to ere on the side of safety and come in well outside the danger zone, and then make their way to the starport at normal space speed, taking a week or more.