Changing Jump Distance

[Spinward Scout]

So I've been wondering about how to change the distance of Jump. I think I've come up with something that could be implemented pretty easily. This is what I had in mind:

Jump 1 = 1 parsec
Jump 2 = 2 parsecs
Jump 3 = 4 parsecs
Jump 4 = 8 parsecs
Jump 5 = 16 parsecs
Jump 6 = 32 parsecs

There wouldn't need to be a change in technology, fuel used, or time in Jump, just a change in description of how Jump works. Basically doubling jump distance traveled with each higher Jump Drive.

Let's say you needed to go 10 parsecs. If you had a big enough drive, you could make a Jump 4 then a Jump 2, two Jump 3s then a Jump 2, etc...

Of course, making the fastest ship able to cross the distance from Core to the spinward edge of the Imperium in 2 months instead of a year would change the dynamic of the large scale Imperium only slightly, but on a small scale it could make a very big difference. X-Boat communications time would be cut in half at maximum - unless the X-Boat routes are re-plotted. Ordering goods from the other side of the sector would only take about a month round-trip if the MegaCorp has fast ships - you could order goods from Core from way out in the Spinward Marches and have them delivered to Efate in less that 6 months as opposed to 2 years. The Imperial Fleet could have a larger patrol range. Small civilian ships would still have short legs, but larger vessels (battleships, passenger liners, heavy freight haulers, etc...) could have a much better ability to get someplace faster. Making that Jump 6 Drive almost magical.

Then again, having to rewrite the navigation rules or misjump rules might be a bother.

So, is this something you would try In Your Traveller Universe? Or has anyone used something similar?

 

[HG_B]

The alternate drive rules in MGT might be of interest to you.

 

[BillDowns]

Of course, making the fastest ship able to cross the distance from Core to the spinward edge of the Imperium in 2 months instead of a year would change the dynamic of the large scale Imperium only slightly, ...

I would have to disagree on this point, but since I am not an OTU fan, I don't really care. I am just noting it will change things radically.

Where this would make a really big difference, whether for MTU or OTU, though is messing with the subsector mapping. Jump 4 will take you completely across a subsector in one hop and Jump 6 is going to cross 3 subsectors the long way (10) and 4 the short way (8).

One time, I did play a game where we adjusted things by altering the time spent in jump. Something like this:
J1 = 168 hrs/parsec
J2 = 84 hrs/parsec
J3 = 56 hrs/parsec
J4 = 42 hrs/parsec
J5 = 33.6 hrs/parsec
J6 = 28 hrs/parsec

Reduces the time spent in travelling but does not screw with the subsector mapping.

YMMV

 

[BillDowns]

A side effect of adjusting the time in jump thing, and what we did in that game I mentioned, was to allow jumps of any size so long as you had the fuel for it. So, a Fat Trader could replace some of its cargo space with fuel tankage, and go 2 parsecs; it just took 2 weeks instead of one.

 

[hdan]

If we're interested in alternative Jump systems...

My son came up with an interesting variant on your suggestion - do the "powers of two" jump thing, but have any jump higher than 4 subtly damage the fabric of space between the two destinations. (His variant was a "warp" drive, not a proper hyperspace drive.)

In his setup, each system accumulated what amounts to "Warp Rads" for high speed (Warp 4+) travel. If you get too many "Warp Rads" (my term, not his) then the system becomes unstable for a period of time and gets an Amber code. Space will "bleed off" the damage over time, but nobody wants to be blockaded while their system recovers.

Overly warped space gives you a greater chance to "mis-warp", and consequently many merchants won't risk a voyage to a zoned planet.

For this reason, it's illegal for commercial traffic to go more than Warp 3 in most places.

Warp-6 is the highest warp you can go without forcing space in on itself, forming a singularity and destroying the ship. Warp-6 is also very damaging to a system - a fleet leaving together at Warp-6 will twist space enough to get the planet "rated". Such an action is usually considered an act of war, and consequently only very specialized ships are rated for Warp-6.

Fuel usage is as per normal Jump drives, but it is a continuous burn; if you cut off the drive half way, you've only used half the fuel. You can use this effect to travel faster if you have a higher Warp number drive or farther if you have more fuel.

 

[aramis]

Jump 1 = 1 parsec
Jump 2 = 2 parsecs
Jump 3 = 4 parsecs
Jump 4 = 8 parsecs
Jump 5 = 16 parsecs
Jump 6 = 32 parsecs

The largest effect would be marginalization of minor worlds more than a jump off route.

For J1-J2, it's no change at all...
J1 up to 6 targets
J2 up to 18 targets
J3 up to 60 targets instead of 36
J4 up to 216 targets instead of 60
J5 up to 816 targets instead of 90
J6 up to 3168 targets instead of 126

Which means the canonical bulk freighters have reasons to be going J4... the cost per parsec will drop to comparable to J2... but it also means major populations will no longer trigger "rest stop communities" ... as with the move from rail to highway, many railway stops will simply die... and as with the move to major highways, many towns "along the way" lose their business as the highway bypasses them. It opens the gravity model up to making the longer hauls competitive, and if at a major hub, being able to jump to a world with sufficient modifiers to make J4 op costs pay off.

Subsidized liners, at J3, can now run hi-to-hi pop.

It also means the fleet can cross a sector a week, meaning the front lines are 2 SECTORS deep. Every world is a target. And suicide raids can hit Vland from the Marches, or Capital from Terra... and the J5 SRW would have seen earth subject to direct operational attack from imperial bases from early on...

 

[shadowcat20]

Makes the J4 and J5 routs through the rift areas worthless also. One or two jumps and you cross the rift rather than many smaller jumps.

 

[robject]

The alternate drive rules in MGT might be of interest to you.

Similarly those in T5.

 

[Shonner]

Here's what you do. A J6 ship can only travel 32 hexes. So you have to plan a bit to figure out how to get where you need to be. It will get you in the general area fast, from which you can take a J4 ship (which only travels 8 hexes) for example to travel the rest of the way (also fast) if needed.

Likewise, J2 can only travel 2 hexes. And J3 can only travel 4 hexes, etc.

Maybe what will happen is that it comes down to EVERYONE ending up waiting for an available seat on a J1 ship to take them to their final stop. That's why they invented monorail.

 

[Spinward Scout]

Hmmm... I might have to think this through a bit more. I didn't realize it would seriously change the dynamic of warfare and leave Capitol open to attack.

Great ideas everybody!

 

[FreeTrav]

I think that if you're going to make a change to the jump drive, you need to be clear in your own mind about what you want to accomplish with the change - if you want to make the universe "smaller", you might use a mechanism like this; if, on the other hand, your goal is to make it less expensive to operate a starship over the standard distances, but not RADICALLY change the universe, perhaps something like the Lyman Drive (http://www.freelancetraveller.com/features/rules/tech/lymanjd.html) might be more appropriate.

In any case, though, you want to "run the numbers" and look at the potential ramifications of your change - a universe in which the Lyman Drive is the standard jump drive will have fewer J1 ships, and the large cargo carriers may actually be smaller than in the OTU, as they won't have to allocate as much volume for fuel to carry the same revenue load. OTOH, making the higher-numbered drives have even greater range may tend to centralize the Imperium more, as more worlds come within the "decision loop" for Capital. Sectors or Domains could become larger, and themselves more centralized, as well.

So, given the above... what did you think to accomplish by using binary jump?

 

[rancke]

I think that if you're going to make a change to the jump drive, you need to be clear in your own mind about what you want to accomplish with the change - if you want to make the universe "smaller", you might use a mechanism like this; if, on the other hand, your goal is to make it less expensive to operate a starship over the standard distances, but not RADICALLY change the universe, perhaps something like the Lyman Drive (http://www.freelancetraveller.com/features/rules/tech/lymanjd.html) might be more appropriate.

I suspect (haven't actually done the calculations) that changing the per ton cost of jump drives to <jump distance squared> megacredits (i.e. MCr1 for J1, MCr4 for J2, MCr9 for J#, etc.) would make the economics work out more like the setting is described (like jump-1 actually being used across more than one parsec). Also make the per parsec cost of travel by J1 scows cheaper than by J2.


Hans

 

[Dragoner]

If I was going to change anything about the way jump works, I would change how much fuel was required and weight of the drive by TL.

 

[aramis]

If I was going to change anything about the way jump works, I would change how much fuel was required and weight of the drive by TL.

Which will directly affect the cost of shipping stuff... More so the longer the jump the ship can do.

Just using HG drive size x5 instead of Jn x Hull x 10% makes J2 and J3 competetive with 2J1... fuel is a major expense in traveller designs.

 

[ShapeShifter]

IMTU I use the awesome power of the...

KILOPARSEC!



My campaign spans most of the MWG.

 

[fiat_knox]

Hmmm... I might have to think this through a bit more. I didn't realize it would seriously change the dynamic of warfare and leave Capitol open to attack.

And Zhdant, and Hivehome, and the core worlds of the Two Thousand Worlds ... Seems that there'd be wars, whether Humaniti had Jump drives or not. A Jump drive capable of longer distances would not screw up mapping of subsectors as such - a parsec's still a parsec - and, by the looks of it, this scheme doesn't make a jot of difference to your basic Jump-1 and Jump-2 ships, since the distances they travel remain the same.

The big difference is that Jump-4 ships have a vast advantage over Jump-3 ships: a J-3 only travels one extra parsec per jump, whereas a J-4 doubles its Jump distance to 8 parsecs - clearly, there would be a space race between civilisations with Jump-3 to reach Jump-4 first. That achievement would result in the clear military advantage to the society which breaks the Jump-4 barrier: rumours of a Jump-5 and Jump-6 would only spur the emerging interstellar civilisations further.

In the OTU, the clearest advantage would be to the Imperials - their Jump-6 vessels would outdistance the Zhodanis' Jump-5 by sixteen parsecs per Jump, meaning that the Imperial core would have far greater access to accurate information about the war than the Zhodani home world. And in any war, accurate information is more precious than what weapons you have.

High Jump levels would also radically affect trade. The lower Jump vessels could still carry free cargoes, inching quietly along the Spinward Main, but if you really need to get a cargo halfway across the sector in a hurry, the most economically sustainable way would be to get a fleet of big Jump-4 ships, large cargo space, and just haul that freight. Since that includes mail, subsidised mail carriers could be very effective in getting word out, resulting in a considerably better - informed populace, a very effective communications network for law enforcement (those warrants for the characters' arrest could be all over the sector in one month, and the characters in their Jump-2 might have barely covered four parsecs) and a much more economically vibrant Imperium.

 

[Shonner]

Hiver manipulation would become more difficult.

 

[fiat_knox]

Nah, they'd just have to get more creative.

 

[Dragoner]

Which will directly affect the cost of shipping stuff... More so the longer the jump the ship can do.

Just using HG drive size x5 instead of Jn x Hull x 10% makes J2 and J3 competetive with 2J1... fuel is a major expense in traveller designs.

Which is something I could live with, it would make small stations and colonies more viable.

 

[saundby]

Running a campaign in the time where a new jump drive technology upsets the economy (and the people in it) could be a lot of fun. Everyone would have an axe to grind. The new economy vs. the old, trying to hold back the change. Fearmongers and the legitimately fearful drumming up the population about the military implications of the new tech.

The adventures just write themselves!