Adventure-Class Ships

[phavoc]

That is not what the game authors said back in the day when they were describing their game.

View attachment 6890

LBB:0

and from The Traveller Book

"Welcome to the universe of Traveller! In the distant future, when humanity has made the leap to the stars, interstellar
travel will be as common as international travel is today."

There are a lot more quotes, but those two will do, especially since The Traveller Book was the first to tie the setting in with the game rule

Unfortunately for the authors, the statement is a bit of a logical fallacy. Airline travel is not equivalent to starship travel. The reason for that is that flight times on an aircraft are greatly different (hours instead of days). People don't have cabins on planes (with a few notable and very expensive exceptions) - they don't spend days on the same aircraft while traveling between their origin and destination.

The closest actual equivalent would be passage by liners in the early 1900s. There you had, roughly speaking, travel across the Atlantic in approximately 5-7 days, depending on the speed of the vessel. Travel at that time was a regular thing and people travelled around the world by ship. The Europe / America crossings were the busiest for the time period, followed by Europe to Asia via the Suez canal.

So the authors in the statement should have actually referred to travel in 1900 and not 1980. Two vastly different periods and modes of travel. The game has had numerous deficiencies when setting up the back story / gaming universe that have stayed as canon through multiple editions and publishers. It's unfortunate that they did not fix this reference, since travel between star systems is an important facet of the game.

 

[Vormaerin]

No one is arguing about how it should be played in anyone's particular campaign. The author's intent or even their explicit statements are not relevant once I start running.

But when having a discussion about the design, they are relevant and handwaving them away just means the discussion is irrelevant. Because everyone is right about IMTU.

 

[phavoc]

Estimating passenger travel between worlds within a subsector, within a sector, or beyond is gonna be a swag - at best. We cannot really compare modern travel to travel back in 1900 because the modes were very different as was cost.

We do know that during the late 1880s and early 1900s - the heyday of the ocean going liner period - travel wasn't cheap. For the wealthy it was obscenely expensive - and they had the resources to pay for it. The rest somehow scraped up enough funds to get one-way passage for their migrations. Business travel wasn't quite the same, though we have many equivalents.

With the great delay in time due to jump space, I'd think that you would see the greatest amount of travel within a limited volume for around a particular world. Assuming a liner with Jump-3 capacity as the norm, for the sake of this example, that would put travel for most to a range of 9 parsecs. And 30 days travel for something is a significant period for anyone - unlike today when people routinely travel for an entire day to get somewhere and we consider that to be a significant time burden. I'd say most travel was point to point, or perhaps 1 stop. That's still a significant distance and investment in both time and credits to do so. But it falls easily within the realm of possibility and plausibility. Both important aspects in my opinion.

I think it was in the early LBB that spoke of one of the worlds near Regina that was a target for colonization from the "core". Travel of that kind of distance for any scale of people pretty much guarantee's the colonists emigrating in cold sleep. For a FAST ship we know it's about 6 months travel from Capital to Regina, or most points within the Marches. A colony ship is gonna be slow and take a far longer period, probably 9-12 months. And that's one-way. So that makes migration possible, but still expensive and time consuming.

I would seriously doubt many people would ever travel outside of their sector for much of anything. Those that could would, most likely, have very specific needs, be very wealthy, or be adventurers playing an RPG game.

 

[swordtart]

Far Trader spreadsheet for the Imperium:
https://www.travellerrpg.com/threads/gt-far-trader-rough-start.41477/

https://www.dropbox.com/s/qy9ac4lktal9o1p/ Imperium GURPS FT.xlsx?dl=1

Calculates BTNs for all worlds in the Imperium (and IIRC surrounding sectors) and sums it up, here for Collace:
View attachment 6896

1 094 162 passengers total for Collace, of which 79 057 (to put a number on the range) from Tarsus.

That's an impressive amount of data. So to get the total traffic in District 268. I just need to put each system in and tot up the totals.

I think it is calculating the BTN incorrectly. My read is that it should be
WTN(Collace) = 5.5
+WTN(Tarsus) = 4
+WTCM = +0.5 (In<->NI)
+ Distance Modifier = 0.
This gives a BTN of 10, but this is capped at 9 because it cannot exceed the smallest WTN+5.

I think the spreadsheet gets 9.5 as the modifier for WTCM is being applied after the cap. The formula is quite difficult to read and BTN is simply the minimum of the calculated value or each WTN+5.

I would swap
=IF( CA3722>0, MIN( IF(MIN($BW3722,CI$2)<5,MIN($BW3722,CI$2)+5,99), $BW3722+CI$2 ) + SUM($CB3722,CD3722:CF3722), 0 )

With
=IF( CA3722=0, 0, MIN( ($BW3722+5), (CI$2+5), SUM($BW3722,CI$2,$CB3722,CD3722:CF3722) ) )

It removes the multiple nested MIN functions that make it difficult to debug and puts the test to remove the reference system out front and gets it out of the way.

 

[rinku]

4+distance for the Astrogator. So a typical far trader jump is 6+ for the Astrogator. So, yeah, you can do various things to get a +4 modifier on that roll. Of course, you didn't even need an astrogator on a far trader in CT. Your vessel had to be more than 200 dtons before that crewperson was needed. On the other hand, your military ship are an 8+ and your rift cruisers and fast tranports are 10+. Before any of the various other modifiers.

Sure, you can say "oh, guess what, they can have computer friends and spend hours on the task and whatever", so the roll is actually still irrelevant. Okay, then the roll is still irrelevant and space travel is super easy. Which was the point. If that's the mechanics of jump, then it's not specific to the Imperial Core. In its inherent in jump drives and the only reason space travel would be problematic is lack of ships regardless of where you are.

Anything that has a failstate that can be represented on a 2d6 roll is catastrophically dangerous by commercial travel standards

Don't forget it's also a known thing if the Astrogator roll has failed, and it's repeatable. You may actually be better off making repeated attempts instead of taking extra time, except for very long jumps. But a sucessful plot IS required to initiate jump.

So the actual Engineering (Jump Drive) task would normally have no worse than a +1 chain task modifier for a sucessful task. If the success effect was as small as +1, they get a +2, which would be expected in almost all cases. Essentially, unless there's unwise stuff involved, even if the Engineer is a rookie (Engineering 0) with no EDU mod, they're rolling 4+, with a +1 for a minimally successful plot, meaning a clean jump on a 3+ and a time delay misjump if they roll a 2. Any Jump Engineer 1 (the skill level required to hold down the job) that graduated high school, will not misjump.

But... sometimes things are out of control. The Engineer is unconscious and the untrained pilot is the one pushing the button, with the jump drive having taken battle damage and 100D 30 minutes too far away...

 

[AnotherDilbert]

That's an impressive amount of data. So to get the total traffic in District 268. I just need to put each system in and tot up the totals.

Yes, but you'll get intra-subsector traffic twice, e.g. Tarsus-Collace traffic will show up both under Tarsus and Collace.

I think it is calculating the BTN incorrectly. My read is that it should be
...
I would swap
=IF( CA3722>0, MIN( IF(MIN($BW3722,CI$2)<5,MIN($BW3722,CI$2)+5,99), $BW3722+CI$2 ) + SUM($CB3722,CD3722:CF3722), 0 )

With
=IF( CA3722=0, 0, MIN( ($BW3722+5), (CI$2+5), SUM($BW3722,CI$2,$CB3722,CD3722:CF3722) ) )

There are two things going on, most of which I had forgotten...

1. I deliberately moved the distance mod and WTCM outside the MIN, to prevent small worlds basically ignoring distance when calculating trade with distant large worlds. I consider that an obvious bug, and hence my modification a bugfix.

WTCM, e.g. allegiance, should (I believe) be applied outside the MIN to reduce sameness, small worlds should not have exactly the same amount of trade with all larger worlds (WTN+5). That is a straight house-rule, I'm afraid.


2. Based on the text around the BTN max, I arbitrarily limited the application to worlds with a WTN of less than 5.

GURPS Far Trader, p15:
... Comparing the economies of 8 billion people and 90 people is like comparing apples and oranges, so some adjustment is necessary to compensate for this:
_ BTN can never exceed the smaller WTN + 5. This prevents extreme results when computing trade between extreme worlds.

I don't think that should apply when both worlds have 8 billion people. Call it an interpretation or house-rule if you wish.
If that maximum is applied to all worlds, large worlds would trade equally much with medium worlds, as with large worlds; e.g. the US would trade equally much with China and Sweden. Again, not a reasonable result.


I agree that moving the kill switch for distance (CAxxxx) = 0 up front would be preferable.


So, it's some sloppy coding, some bug fixing, and some house-rules, but I meant the formula as it is executed. Comments in the code would have been great. I had forgotten how much I had modified the formula. Sorry about not telling you about it up front, but it's a spreadsheet: just change what you don't like...


Interestingly, I can still understand my own code five years later.

 

[Talon Greyfeather]

Don't forget it's also a known thing if the Astrogator roll has failed, and it's repeatable.

Not at my table. IF a roll for Astrogation and Jump are necessary then that means something went wrong and they aren't following standard procedures. I make the rolls blind. They can find out what happens when they exit jump and try to determine where they are.

Besides, I get to enjoy the look on their faces when they see my expression and then have to wait until next session to find out the result

 

[Vormaerin]

Any time you can roll until you succeed, you shouldn't be rolling in the first place.

 

[rinku]

Any time you can roll until you succeed, you shouldn't be rolling in the first place.

Well, if time is critical it's not academic, especially on a long jump. And there is almost always SOME deadline for having completed the Jump plot.

But players DO like to make those dice rolls.

In another context, writing a book is the sort of task where you can assess how well you did and can repeat it until done. But publisher's deadlines loom...

Picking a lock is another example. You can keep trying until you succeed, but if the crate contains all the food you probably only have days.

 

[swordtart]

Don't forget it's also a known thing if the Astrogator roll has failed, and it's repeatable. You may actually be better off making repeated attempts instead of taking extra time, except for very long jumps. But a sucessful plot IS required to initiate jump.

This is perhaps somethings that needs some house ruling. There is no reason for a dedicated Astrogator not to keep retrying the check until they roll a double 6 and get the best result they could get. It takes minutes and most transits are hours to days. Frankly you can take your time and still have many goes (and get an extra +2 on your effect when you roll those double sixes). Since it is also the ONLY thing the Astrogator does they might as well spend the whole time out to 100D doing it. This virtually guarantees a +3 on the task chain (for short Jumps at least).

According to the rules the plot doesn't stale out in the time transits might take (and IIRC this has been canon since early on as you could buy a jump tape with a pre-plotted course). It sounds logical that system based Astrogators would sell optimal plots as a service. You can then have a plot that prevents you obtaining the necessary plot because of "reasons".

The Engineer therefore becomes the only important role (and at least has a role the rest of the trip). The Engineer however can also be easily replaced/complemented by a wholly competent droid. This makes ordinary short jumps entirely predictable (which you would expect for something that is done routinely). Liners should not realistically suffer the tragic mis-jumps that seem to permeate the scenarios*

However I would anticipate that most player ships will probably have Astrogation as a secondary skill for the Pilot (as those skills often sit together in skill tables) rather than having someone who sunk all their skill opportunities into gaining Astrogation as a specialism (e.g. by going to University (and even then majoring in Engineering(Jump) makes sense), so they may well be operating at level 1-2. They may also have other jobs to do in transit limiting the time they can spend on the Astrogation task.

As you say later in your post it is only an issue in rare cases when you want to emergency jump and even then it is probably the least of your problems. Mis-jumps are probably better treated as a plot element rather than a random occurrence. Astrogation skill is also woefully under utilised.

*If you could jump into the 100D (with the same penalty as jumping out from within the 100D) that would at least justify some of the "mis-jump because of short-cuts" logic. Astrogation is woefully under-used skill (for one that is all but mandated for players to sink skill acquisition opportunities on). The mechanics of in-system travel do not really lend themselves to logically extending the skill into other areas that seem more suitable for the Pilot skill. Astrogation skill might as well be subsumed into Engineer(Jump) and Pilot.

 

[swordtart]

Interestingly, I can still understand my own code five years later.

It's certainly not as bad as debugging code written by a team of programmers of indeterminate skill and with "quirky" styles, who misunderstood the syntax of the already pretty arcane 1960's era language it was written in, 30 years after it was first written, for a different platform and where the comments had been explicitly purged and obfuscated because the code maintenance contract was about to be cancelled.

Finding the anomaly and restoring the book implementation in your code took minutes

 

[Terry Mixon]

This is perhaps somethings that needs some house ruling. There is no reason for a dedicated Astrogator not to keep retrying the check until they roll a double 6 and get the best result they could get. It takes minutes and most transits are hours to days. Frankly you can take your time and still have many goes (and get an extra +2 on your effect when you roll those double sixes). Since it is also the ONLY thing the Astrogator does they might as well spend the whole time out to 100D doing it. This virtually guarantees a +3 on the task chain (for short Jumps at least).

According to the rules the plot doesn't stale out in the time transits might take (and IIRC this has been canon since early on as you could buy a jump tape with a pre-plotted course). It sounds logical that system based Astrogators would sell optimal plots as a service. You can then have a plot that prevents you obtaining the necessary plot because of "reasons".

The Engineer therefore becomes the only important role (and at least has a role the rest of the trip). The Engineer however can also be easily replaced/complemented by a wholly competent droid. This makes ordinary short jumps entirely predictable (which you would expect for something that is done routinely). Liners should not realistically suffer the tragic mis-jumps that seem to permeate the scenarios*

However I would anticipate that most player ships will probably have Astrogation as a secondary skill for the Pilot (as those skills often sit together in skill tables) rather than having someone who sunk all their skill opportunities into gaining Astrogation as a specialism (e.g. by going to University (and even then majoring in Engineering(Jump) makes sense), so they may well be operating at level 1-2. They may also have other jobs to do in transit limiting the time they can spend on the Astrogation task.

As you say later in your post it is only an issue in rare cases when you want to emergency jump and even then it is probably the least of your problems. Mis-jumps are probably better treated as a plot element rather than a random occurrence. Astrogation skill is also woefully under utilised.

*If you could jump into the 100D (with the same penalty as jumping out from within the 100D) that would at least justify some of the "mis-jump because of short-cuts" logic. Astrogation is woefully under-used skill (for one that is all but mandated for players to sink skill acquisition opportunities on). The mechanics of in-system travel do not really lend themselves to logically extending the skill into other areas that seem more suitable for the Pilot skill. Astrogation skill might as well be subsumed into Engineer(Jump) and Pilot.

Astrogation is also for normal space navigation. Also not heavily utilized, but it’s part of it.

 

[Anstett]

The only IMU thing that I added to Astrogation is the System Time Sync as part of an RP note for arriving at 02:15 and the middle of the night watch.

Dragonslayer Space | Main / Astrogation

 

[Condottiere]

Astrogation can be offboarded.

 

[phavoc]

I've always treated it as you can check your math up to the point of jumping. But, the proof is in the pudding and if somewhere you input some wrong figure or your reference data wasn't fully up to date, you'll pop out not where you thought you were going to pop out.

So the dice roll is really about your emergence. And even plotting everything exactly, there's always some potential risk of missing your PLANNED emergence point. Sure, you should always hit the right star system, but after that, just how far off your planned emergence point is your skill and die rolls. All the other things that can be combined - running while under fire and maneuvering, maybe having a glitchy software package, etc, can all be factored into how far off from your planned destination.

Unless you are jumping in the 100D limit or something other than that, you are going to get to where you planned to go - just how far off is the question.

 

[rinku]

This is perhaps somethings that needs some house ruling. There is no reason for a dedicated Astrogator not to keep retrying the check until they roll a double 6 and get the best result they could get. It takes minutes and most transits are hours to days. Frankly you can take your time and still have many goes (and get an extra +2 on your effect when you roll those double sixes). Since it is also the ONLY thing the Astrogator does they might as well spend the whole time out to 100D doing it. This virtually guarantees a +3 on the task chain (for short Jumps at least).

Yeah, maybe not so much. The time factor for that roll is 1D6 x 10 minutes - 10- 60 minutes. An average per trial of 35 minutes. 1 in 36 chance of rolling a 12, so you'd expect that to take around a day, not "minutes", unless they got lucky.

But to be fair, you probably never need to roll boxcars either, especially if your Astrogator is any good. It's a task chain, so the thresholds are +1 for a +0 success, +2 for an effect of 1 to 5, +3 for an effect 6+. The +3 threshold is generally a low priority, given that the Engineering roll is only 4+. A +2 bonus will mean a safe jump, even for an EDU6 Engineer zero.

So sure. If you roll up a mere exact success, try again. You probably do have enough time to get that Effect 1 or more.

 

[Uqbarian]

Far Trader spreadsheet for the Imperium:
https://www.travellerrpg.com/threads/gt-far-trader-rough-start.41477/

https://www.dropbox.com/s/qy9ac4lktal9o1p/ Imperium GURPS FT.xlsx?dl=1

Calculates BTNs for all worlds in the Imperium (and IIRC surrounding sectors) and sums it up, here for Collace:
View attachment 6896

1 094 162 passengers total for Collace, of which 79 057 (to put a number on the range) from Tarsus.

Thanks for sharing this. Let me tell you, it's miles cleaner than my unholy kludge of a trade spreadsheet.

 

[swordtart]

Yeah, maybe not so much. The time factor for that roll is 1D6 x 10 minutes - 10- 60 minutes. An average per trial of 35 minutes. 1 in 36 chance of rolling a 12, so you'd expect that to take around a day, not "minutes", unless they got lucky.

Agreed, I meant they may as well keep TRYING for the double 6 until they reach the jump point not that they are guaranteed to get it. If the main is close to the sun or you wild refuel off a gas giant prior to jump transits at 1 G can take well over a day and you can have the option of multiple attempts even when taking your time*.

There appears to be no stale out for the check so in theory they could actually be rolling from the minute they enter the system.

Also while the Robot Handbook imposes a penalty on non-sentient Astrogation it is only -2 if a human with adjacent skill reviews it (like the pilot). Even if we apply this to Expert Systems running Astrogation autonomously on conventional computers they can achieve effect 6+ for short jumps with equipment and software costing much less than an Astrogators monthly wage. You could run several instances (or have several computers running in parallel) and make dozens of checks in even a short transit.

If a crewmember other than the main Astrogator has even has minimal skill 0 (Scout and Scavenger get this as Basic Training) they can run a dirt cheap expert package and either work together to improve the main Astrogators chance or just run in parallel and provide an alternative plot for the pilot to select.

As you say, you don't need a particularly good roll to get the +1 or +2 and a competent Engineer on a properly maintained ship should be making that roll even without any modifier from the Astrogator.

If you have no house rules to prevent these sorts of dodges then plausibly they would be standard practice.

*Depending on the roll you require in many cases you could actually go faster. Whilst you reduce your chance of success, you can on average make 10 times the attempts. If you need to roll 9+ for example you have 10/36 chance of making it. If you make that 11+ by going fast then you have 3/36 chance of making it, but you get 10 attempts (which works out to 20/36 overall - and you flatten the probability curve).

 

[swordtart]

*Depending on the roll you require in many cases you could actually go faster. Whilst you reduce your chance of success, you can on average make 10 times the attempts. If you need to roll 9+ for example you have 10/36 chance of making it. If you make that 11+ by going fast then you have 3/36 chance of making it, but you get 10 attempts (which works out to 20/36 overall - and you flatten the probability curve).

Ooh this is a thing! If you can keep retrying without penalty, with a 1Dx10 minute task it is almost always better to rush the job as a 1D minute task. If it means you need to roll more than 12 it obviously doesn't help, otherwise even if you normally need a 2+ and cannot fail, having 10 rolls at 4+ means you have a 35.999999/36 chance of success and you have a 99.5% chance of succeeding after 3 minutes less than 1/3rd of the 10 minute minimum if you took the normal amount of time.

I wonder how many other times going faster is actually quicker than taking the normal time (or going faster). Spreadsheet Stand To!!

EDIT:
It transpires that if you can get your required effect by rolling 9 or less you can rush and it only takes 3 attempts before your cumulative chance of success is greater than taking the normal roll. If you need to roll 10 it takes 7 attempts (and clearly if you need to roll 11 or 12 you cannot rush anyway). If you need to roll only 2 3 attempts will give you an almost certain chance (99.999%) but obviously it will never be 100% certain, it will likely be much quicker). As the majority of time increments are at least a factor of four lower than the next then as long as you can keep trying without penalty the majority of the time it is better to go faster and have more goes at it.

 

[rinku]

In any case, the practice of not bothering to make the rolls when the result is certain or does not matter IS part of core Traveller play.

But the PLAYERS do like to make those rolls. And you can reward them with narrative stuff like a superb Jump Plot or Engineering roll bringing the ship in at a slightly better emergence point (Traveller Companion has a discussion on that). It's only the MISJUMP that's guaranteed to be avoided if your target is 2+ or better. A low roll might mean an extra half hour of 100D transit time - usually irrelevant... unless there's a nearby pirate...