## Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Discuss the Traveller RPG and its many settings
Moppy

### Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

I couldn't find anything with google.

Is there a list of systems that require jump N to reach from Capital, Soloman(?) etc, or ones that require a major detour for lower jump?

Has someone already written software to calculate this from Traveller map?

Reason why I am thinking about this is that I'm deciding what jump range is needed for a particular class of craft.
Old School
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Traveller map will calculate the most efficient route for J-1 through J- 6 if you give it two systems and the jump number.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Old School wrote:
Tue Jul 09, 2019 10:51 am
Traveller map will calculate the most efficient route for J-1 through J- 6 if you give it two systems and the jump number.
I'd have to do it for every system. I was hoping someone has a list of "these systems need jump 3/4/5/6". (edit: Yes, there ways to shortcut the process probably a bit off topic for here, but I'l happily discuss graph algorithms if someone wants to).

I guess I'll leave it until I have some free time.
Old School
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Other than systems within rifts, I don't think there is anywhere you can't reach with Jump 3. There are very few places you can't get to with jump 2, although jump 3 sometimes gives a significant shortcut. I'd guess over 99% for jump 2. Jump 3 is everything not in a Rift.

Travelling from Capital, Jump 4 will allow you cross the Reft sector, avoiding a significantly longer route to get to the Trojan Reach (and to a lesser extent, Spinward Marches and portions of Deneb). The Hierate Jump 5 route is the most extreme example of "going the long way around" to get from the Hierate to its Colonies if you don't have jump 5, but there probably aren't 10 non-rift systems combined in either Hierate that you can't get to with Jump 2.

Look at the traveller map zoomed out and find the spots of relatively low start density. For example, Trojan Reach has the "outrim void" from the middle of the sector to the Spinward/coreward corner. But you can get to every system with jump 3. Other than rifts, I've never seen a system that can't be reached by jump 3.
DickTurpin
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

As a general rule, military ships have jump-4 or higher, while civilian ships have jump-3 (rare) or less. I could see a luxury passenger liner with jump-4 but freight gets too expensive if moved in high jump number ships. Some areas where inhabited stars are far apart might have exceptions to the general rule.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

According to traveller map, regina to capital can't be done at jump 2 without leaving imperial space.

I couldn't be bothered to find out where the problem was. Probably somewhere in the thin bit of the top of the claw. If that's true then this probably applies to most of the marches.

edit: Actually the problem is further towards the capital than the corridor. That surprised me. I stopped looking for the problem again.

edit: I wonder if there's some system marked as "not imperial" by accident, or maybe it's some weird client state that technically isn't imperial but in practise is?
Old School
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Traveller map will draw you the route its plotted.

Definitely is an error somewhere. The route it plots for me runs just north of imperial space in corridor. But there are clearly plenty of jump 2 options through that section of imperial space.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

It works in one direction only.

Regina to Capital, J-2, Imperial worlds only, works fine.

In reverse, Capital to Regina, it stops at Brariun and is forced to leave the Imperium, re-entering at Durima. If told Imperial worlds only, it fails to find a route.

That doesn't look like a data problem, and sounds like a logic error in the pathfinding.
Condottiere
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

In theory, you could have double bunkerage capacity and transition twice, depending on the empty hex ruling your dungeon master is adhering to.
InexorableTash
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Moppy wrote:
Fri Jul 12, 2019 12:28 pm
It works in one direction only.

Regina to Capital, J-2, Imperial worlds only, works fine.
Nope - it only looks like it does. If you limit the path to Imperial Worlds it will report "No route found".

The Regina-Capital route passes through Wal-Ta-Ka (Deneb 2713) which is not an Imperial world (allegiance code is NaHu). There is a grouping of such worlds as well as some client state worlds (CsIm) in the Atsah subsector; just enough to form a gap.

These worlds appear within the Imperial borders because borders are not official in the way world allegiances are; they're just a way to show information about groups of worlds. A hole in the borders would be possibly more accurate, but ugly. Also, you get what you pay for. Register complaints at your local TAS office. Without passing through those worlds, you can't make it Regina-Capital at J2.

Edit: Moppy called this out above, but didn't identify the specific worlds.
In reverse, Capital to Regina, it stops at Brariun and is forced to leave the Imperium, re-entering at Durima. If told Imperial worlds only, it fails to find a route.
FWIW, many routes between two points are often possible; the code doesn't care about anything but minimizing the number of jumps. That does lead to odd effects like this, where the route wanders coreward and out of the Imperium then back in. Visually, it looks longer than a "straight" shot down the Imperial worlds in Corridor, but the hex distance is the same (since you can't ever go directly spinward/trailing because hexagons)
Last edited by InexorableTash on Sat Jul 13, 2019 5:15 pm, edited 1 time in total.
phavoc
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Any ship is capable of carrying water as cargo, pumping that water from cargo to your fuel tanks and using it raw or converting to lhyd, then emerging from jump in deep space and jumping again to your destination.

That's permissible under the rules. But for a freighter it means your travel is going to be light on profitable cargo, so changing regions has a sunk cost to it. Or else you are transporting high value low bulk cargo.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

InexorableTash wrote:
Fri Jul 12, 2019 7:31 pm
In reverse, Capital to Regina, it stops at Brariun and is forced to leave the Imperium, re-entering at Durima. If told Imperial worlds only, it fails to find a route.
FWIW, many routes between two points are often possible; the code doesn't care about anything but minimizing the number of jumps. That does lead to odd effects like this, where the route wanders coreward and out of the Imperium then back in. Visually, it looks longer than a "straight" shot down the Imperial worlds in Corridor, but the hex distance is the same (since you can't ever go directly spinward/trailing because hexagons)
In this case, clicking the reverse icon (the double arrows) cleared the "imperial only" custom setting which is why it worked one way and not the other way.

After matching settings, I still find it picks a different route forwards, to the route in reverse. This is kind of weird. I would expect a mapping tool to give the same route in both directions.

One quick fix you can make if you don't have the time to change the algorithm, is run it in each direction, then reverse one route, then take the 1st route in alphabetical order. It's a bit boneheaded but it's quick to implement. I'm not sure what you're paying on server costs, but it's probably cheaper than several hours of your time.
WingedCat
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Old School wrote:
Tue Jul 09, 2019 10:51 am
Traveller map will calculate the most efficient route for J-1 through J- 6 if you give it two systems and the jump number.
It'll even do Hop-1. Just tell it you're doing J-10. I haven't tested, but I suspect this will support any similar drive in Traveller: J-20 for Hop-2, J-100 for Skip-1, et cetera.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

WingedCat wrote:
Sun Jul 21, 2019 5:36 am
Old School wrote:
Tue Jul 09, 2019 10:51 am
Traveller map will calculate the most efficient route for J-1 through J- 6 if you give it two systems and the jump number.
It'll even do Hop-1. Just tell it you're doing J-10. I haven't tested, but I suspect this will support any similar drive in Traveller: J-20 for Hop-2, J-100 for Skip-1, et cetera.
hop 1 isn't same as jump 10. hop 1 can't do less than 10 unless you make a special, tricky dice roll.
WingedCat
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Moppy wrote:
Sun Jul 21, 2019 8:25 am
WingedCat wrote:
Sun Jul 21, 2019 5:36 am
Old School wrote:
Tue Jul 09, 2019 10:51 am
Traveller map will calculate the most efficient route for J-1 through J- 6 if you give it two systems and the jump number.
It'll even do Hop-1. Just tell it you're doing J-10. I haven't tested, but I suspect this will support any similar drive in Traveller: J-20 for Hop-2, J-100 for Skip-1, et cetera.
hop 1 isn't same as jump 10. hop 1 can't do less than 10 unless you make a special, tricky dice roll.
Which many hop-1 users do on a routine basis, as I understand it.
AnotherDilbert
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

WingedCat wrote:
Moppy wrote: hop 1 isn't same as jump 10. hop 1 can't do less than 10 unless you make a special, tricky dice roll.
Which many hop-1 users do on a routine basis, as I understand it.
There is nothing routine about nailing a hop-1.

In T5.09 you have to roll skill or less with about 10D, so basically impossible. You can only abuse the task mechanism and hope for a Spectacular Success, which gets more likely the more dice you roll. Unfortunately Spectacular Failure gets equally more likely...

If you want to jump with an about 50% chance of Spectacular Failure, go right ahead...
Linwood
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Sounds like trade routes where hop drives are common would look a lot like the current hub-and-spoke networks - hop-drive vessels serving trade nexi 10+parsecs apart with jump drive vessels serving the vessels in between.

Gives “flyover state” a whole new meaning....
Condottiere
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

It really comes down to how hard the thirty two point six light year hop is.

If it's an absolute, you have to build hubs equidistant from each other.
Moppy

### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Condottiere wrote:
Tue Jul 23, 2019 3:09 pm
It really comes down to how hard the thirty two point six light year hop is.

If it's an absolute, you have to build hubs equidistant from each other.
T5 allows 9-10 hexes. not sure if it goes to 11. Their rules are hard to read.
Condottiere
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### Re: Is there a list of systems that require jump N to reach, or ones that require a major detour for lower jump?

Once you know how much leeway there is, you can toy with the mechanics.

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