A silhouette of 3 is an tie fighter would be 9. A star destroyer is silhouette 8 which would be a 64. Which would mean that it only takes 7 tie fighters to fuel a star destroyer. The difference between a starfighter and a freighter is less than double. Using your example that would be like a car with 10 gallons of gas and semi with 20 gallons of gas... Really I thought I was low balling it with using a cube.

^2

Squaring or cubing quickly erodes potential profit from any shipping run, and defeats the economy of scale pretty quickly as well.

Simple test case: YT-1300 (Sil4) vs Space Master (Sil5). The Space Master has almost 5 times the capacity (800 vs 165), but part of the trade off is the low speed and terrible handling. Say the fuel is 25cr per fuel cell @ Sil1. For most ships, this gives you 50 jumps, or 50 hours of flight time, which, keep in mind, isn't a lot. If you track this in your game, fuel will always be an important factor no matter what. To load a ship from empty:

Cost * Sil (YT-1300) = 25 * 50 * 4 = 5000cr

Cost * Sil (Space Master) = 25 * 50 * 5 = 6250cr

If you square that:

Cost * Sil^2 (YT-1300) = 25 * 50 * (4^2) = 20000cr

Cost * Sil^2 (Space Master) = 25 * 50 * (5^2) = 31250cr

Cubed:

Cost * Sil^3 (YT-1300) = 25 * 50 * (4^3) = 80000cr

Cost * Sil^3 (Space Master) = 25 * 50 * (5^3) = 156250cr

I'm not sure it makes sense for the ship to cost the same as the fuel for 50 hours of flight time...

The simple multiplier seems well within the tolerance range of a decent profit margin, accounts for economies of scale vs ship performance, and doesn't assume it costs the same to keep a Space Master up as a YT-1300.

Using the cubed method you can move five times the cargo at only twice the cost. You still make money through economies of scale. Or you could use another ship like an Action VI Bulk Transport (10,000 vs 800) which is also silhouette 5.

I do agree that the costs are too high. Perhaps drop the 25cr per unit down to around 1 or 2?

^2

Cost * Sil (YT-1300) = 25 * 50 * 4 = 5000cr

Cost * Sil (Space Master) = 25 * 50 * 5 = 6250cr

That seems plausible.

If you square that:

Cost * Sil^2 (YT-1300) = 25 * 50 * (4^2) = 20000cr

Cost * Sil^2 (Space Master) = 25 * 50 * (5^2) = 31250cr

Hmm. If you use the power-of-two law, then maybe the base cost should be 5cr, which would make these final costs much more reasonable:

Cost * Sil^2 (YT-1300) = 5 * 50 * (4^2) = 4,000cr

Cost * Sil^2 (Space Master) = 5 * 50 * (5^2) = 6,250cr

Cubed:

Cost * Sil^3 (YT-1300) = 25 * 50 * (4^3) = 80,000cr

Cost * Sil^3 (Space Master) = 25 * 50 * (5^3) = 156,250cr

I'm not sure it makes sense for the ship to cost the same as the fuel for 50 hours of flight time...

Right. So maybe here, we need to make the base fuel cost more like 1.25 credits instead of 25:

Cost * Sil^3 (YT-1300) = 1.25 * 50 * (4^3) = 4,000cr

Cost * Sil^3 (Space Master) = 1.25 * 50 * (5^3) = 7,812.50cr

So, now let’s look at what it would cost to completely refuel a Sil8 Star Destroyer using these rules:

Cost * Sil^2 (SD) = 5 * 50 * (8^2) = 16,000cr

Cost * Sil^3 (SD) = 1.25 * 50 * (8^3) = 32,000cr

Wow. Those are incredibly low. I need to do some more work on the math on this. ;(

Okay, table 3.4 at https://fas.org/man/gao/nsiad98001/c3.htm shows the lifecycle fuel costs for a conventional aircraft carrier to be approximately $738M. Per year, that’s about $14.75M, or $1.23M per month, just for fossil fuel alone.

Initial acquisition cost is about $2B.

In contrast, a Victory-class Star Destroyer only costs 50Mcr for initial acquisition.

So, if lifecycle fuel costs are comparable, that would mean you’d be looking at roughly 36.9% of the initial purchase price in fuel costs alone, over the lifecycle of the craft. If a Star Destroyer is supposed to normally last fifty years, that would be 18.45Mcr over the life, or 369Kcr per year, and just 30,750cr per month.

That also seems really low. But the percentages are the same.

Dang. FFG didn’t make these things cost nearly enough. ;(

Can I just point out that these rules were not designed to take into account Capitol class ships like star destroyers, which I envisioned had engines of a totally different nature.

Like comparing ships with Diesel engines with ships that have nuclear reactors.

Using what I've written to determine fuel costs for a star destroyer will throw up numbers that make no sense.

I purposely designed them to cover ships up to sil5. And made the presumption anything larger had different types of reactors.

But all the feedback is vey welcome regardless.

As for squaring the sil, it's interesting but might add complexity. Plus my group who do not earn that much cash already find using the rules I've written that fuelling the ship is a struggle, which I intended. I would need to look at my payouts to my group if I was going to up the cost of fuelling their ship. But I think I pay out far less than a lot of groups.

I am more than happy to work in your suggestions however

Keep them coming

RD

RebelDave this is truly well done work! I have one request though: Could you add as a last page a back cover maybe?

I could print it out in bookform for myself that way.

Nicely laid out, and some good information, but I don't really understand the fuel cell thing. A fuel cell seems to cost a specific amount (modified by starport grade), and you use a "fuel cell"s worth of fuel for certain activities. But this doesn't seem to be tied to Silhouette at all, so the cost of, say, one hour of atmospheric flight seems to be the same regardless of whether it's a Sil4 or Sil5 or even larger ship. Undoubtedly it would cost more to keep larger tubs in the air, but these costs don't reflect that.

I would think the solution to this would be simple: every ship has a basic 50 fuel cells, and the cost of each cell depends on the starport grade * Silhouette. Extra cells could be added via Hard Points.

As with anything in the book, its suggestions. Feel free to change the general sum of fuel cells according to the specific ship. Take note that we tried to emphasis that consumption calculation is in accordance with the "effective way of hauling cargo", shortest route and such. Also as Dave commented, we acknowledge your calculation and will adept accordingly.

Moreover, to compare to real fuel consumption and value is irrelevant, this are spaceships in the age of mystics and lasers

I've done something similar myself, not quite as elaborate though.

To ease book keeping, I equaled 1 h of HS travel to 1 fuel cell (and thus 1 space combat, 1 d of sublight travel, or 5 cells for one jump). I set the price at 5 cr for Sil. 3, 10 for Sil. 4 (doubling with every step) and rarity at 2. The number of cells is the ship's Consumables in days x5.

Oh, and the fuel consumption in HS is calculated for x1 travel duration, regardless of hyperdrive multiplier. I deem it silly faster drives to be more fuel efficient.

I really do like how you're handling maintenance and failures. I'll implement that just as written.

Moreover, to compare to real fuel consumption and value is irrelevant, this are spaceships in the age of mystics and lasers

I find this a disappointing response. If you're going to take the "it's not real anyway" argument, then why did you make this supplement at all? Why do star ports have grades? Why does maintenance have a cost? Why not make the players pay whatever you feel like at the moment?

Presumably you wanted "more detail", and it seems to me that, generally, your assumptions of what constitutes greater detail is based on expectations directly derived from "our world". Otherwise the numbers for everything in your work would be completely arbitrary. But they don't appear to be, most of your number choices appear to be trying to fit the numbers into a larger framework that includes economics and physics. So the fuel costs aren't irrelevant, they break the verisimilitude of what is otherwise a decent framework.

First and foremost, I hold no responsibility for the crux of the content, this is Dave's work and I helped mainly in review and edit.

I would say that the numbers are arbitrary or derived from the D6 content, but it dose not mean they have something to do with real life elements. Spaceships are not cars, the fuel is used only for moving, and as we established in the supplement fuel is for more then just for flying. As for framework, its derived from established fluff in the roleplaying games and from the movies, which is very different from cars, boats and planes.

This is awesome content. A great thanks for putting this together!

Argh! OK...

I need to read everything posted so far, and ill edit this post with my replies.

Jeeez.... I dont get this forum software... I tried to multiquote to answer everyones questions, and I says ive quoted too many....

then it wont let me edit to delete the quotes...

then it deletes my entire reply....

Speaking only for myself, I think that this is awesome work, and my biggest difficulty is trying to fully understand all the nuances.

And to help me do that, I have to go back to some real-world numbers and see how they compare. I’m perfectly fine with throwing them out at the end and saying “well, it’s just a game and the numbers are meaningless”, but I still need some sort of frame of reference.

I’m still processing what has been provided here. With regards to how things function mechanically at a deeper level, it’s going to take me some time to work everything out.

So, don’t take too seriously any criticism I’ve provided so far on this topic. I’m not done yet with understanding and integrating this into my mental worldview.

OK.

I didnt relate it to Silhouete, because I figure larger ships were slower, and thus would naturally spend more fuel

This was wrong now I look at it, but I dont know how it would scale. So I have no issue making it a thing.

*However, I did intend (I think i mentioned it in a sidebar) that ships of Sil6 and above these rules wouldnt apply. They would have different drive systems, much like an Aircraft carrier has a Nuclear reactor to drive steam turbines, that draw water from the oceans it travels in. Totally different to a diesel powered ship.

*

I prefered Fuel Cell over Energy Cell, as I like the idea of canisters or tanks of fuel that can explode, be it 'Diesel' 'petrol' 'liquid metal' or some other kind of chemical.

A cell for me (in my mind) is just that... a predetermined 'measure of volume' but of course, that is vague... intentionally, so it can be any amount you want.

*The whole Cube and Square the numbers thing went over my head, numbers hurt my noggin, so I would need to look at it, but I didnt want ships to be TOO expensive.... but then I dont pay my players much in credits... yes, if i upped the costs of running a ship, and upped their payouts, it would balance out. So keep going with this!

More to follow..

Nicely laid out, and some good information, but I don't really understand the fuel cell thing. A fuel cell seems to cost a specific amount (modified by starport grade), and you use a "fuel cell"s worth of fuel for certain activities. But this doesn't seem to be tied to Silhouette at all, so the cost of, say, one hour of atmospheric flight seems to be the same regardless of whether it's a Sil4 or Sil5 or even larger ship. Undoubtedly it would cost more to keep larger tubs in the air, but these costs don't reflect that.

I would think the solution to this would be simple: every ship has a basic 50 fuel cells, and the cost of each cell depends on the starport grade * Silhouette. Extra cells could be added via Hard Points.

As I said, I never intended these rules to be used with ships of Sil6 and above. See my previous post

Nicely laid out, and some good information, but I don't really understand the fuel cell thing. A fuel cell seems to cost a specific amount (modified by starport grade), and you use a "fuel cell"s worth of fuel for certain activities. But this doesn't seem to be tied to Silhouette at all, so the cost of, say, one hour of atmospheric flight seems to be the same regardless of whether it's a Sil4 or Sil5 or even larger ship. Undoubtedly it would cost more to keep larger tubs in the air, but these costs don't reflect that.

I would think the solution to this would be simple: every ship has a basic 50 fuel cells, and the cost of each cell depends on the starport grade * Silhouette. Extra cells could be added via Hard Points.

I like this idea, though I would have it scale a lot faster. Something like: Starport Grade * Silhouette^3. Bigger ships should be much more expensive to keep flying.

^2

I think I left this vague to allow GMs to tweak their own rules... but then I dont use the Availability rules much (PreGen adventures mostly), but if someone wants to collaborate on developing this, I am willing for input!

RebelDave this is truly well done work! I have one request though: Could you add as a last page a back cover maybe?

I could print it out in bookform for myself that way.

Will endeavor to add this!

Moreover, to compare to real fuel consumption and value is irrelevant, this are spaceships in the age of mystics and lasers

I find this a disappointing response. If you're going to take the "it's not real anyway" argument, then why did you make this supplement at all? Why do star ports have grades? Why does maintenance have a cost? Why not make the players pay whatever you feel like at the moment?

Presumably you wanted "more detail", and it seems to me that, generally, your assumptions of what constitutes greater detail is based on expectations directly derived from "our world". Otherwise the numbers for everything in your work would be completely arbitrary. But they don't appear to be, most of your number choices appear to be trying to fit the numbers into a larger framework that includes economics and physics. So the fuel costs aren't irrelevant, they break the verisimilitude of what is otherwise a decent framework.

I dont agree with Rusak here, to be fair he helped with editing more than rules, and I think he might have explained things badly... I am about making it realistic, while keeping it within the vagueness of the system and within the world of SW.

This is awesome content. A great thanks for putting this together!

Very welcome! Glad you like it!

I love this, so much so I'd love to see you team up with the guys who mad the 'Starship wear and tear' rules, 'Starship repair' rules, and the 'speculative trading' rules to create a compendium of deep dive cargo hauling rules.

One minor issue, you never mentioned a difficulty for anyone wanting to do maintenance themselves and factors that may effect that. For example...maybe the more hours you have racked up the difficulty increases and that is further modified by hull trauma and system strain, causing upgrades, and setback respectively?

Idk. For my game's economics, fuel and crit repairs works like so:

Fuel for 1 Month of Hyperspace Travel: Silhouette squared * 100. So 1600 credits for their freighter. Not too bad, I think. Should I have made this per week?

Crit Repair: Silhouette squared * severity of crit * 100

What do you think?

I love this, so much so I'd love to see you team up with the guys who mad the 'Starship wear and tear' rules, 'Starship repair' rules, and the 'speculative trading' rules to create a compendium of deep dive cargo hauling rules.

One minor issue, you never mentioned a difficulty for anyone wanting to do maintenance themselves and factors that may effect that. For example...maybe the more hours you have racked up the difficulty increases and that is further modified by hull trauma and system strain, causing upgrades, and setback respectively?

No... I didnt... the idea was if someone kept on top of maintenance, things wouldnt go wrong, and the cost of that would be determined by the results on the dice. (Mechanics check, success and Advantage reduce time and cost, while Threat would increase cost (more needs to be done), while failure means things might get missed).

The difficulty would be when something HAS gone wrong (You've rolled on the Systems failure table), and the result determines the difficulty of the malfunction.

System strain recovers on its own (per RAW in the CRBs), and HT is repaired separately as per the CRBs.

But theres nothing stopping you modifying what ive done for your own table

As for the other rules you mention, if they are the ones I think they are, Kainrath made a suggestion about combining his and mine (Which is on the table, if he wants to to so), and he also proofread mine.

And Hoolys Spec Trading, well its the same deal really... Hooly does his own Layout work, and I wouldnt want to impose on his own work.

The wear and tear rules you mention... im not familar with, but I would love to look at them!

Idk. For my game's economics, fuel and crit repairs works like so:

Fuel for 1 Month of Hyperspace Travel: Silhouette squared * 100. So 1600 credits for their freighter. Not too bad, I think. Should I have made this per week?

Crit Repair: Silhouette squared * severity of crit * 100

What do you think?

Nice and simple, if it works for you, I like it...

My rules go into abit more day to day expense, but my players like that nitty gritty detail..

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

Erm,.... ahm... er?

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

Erm,.... ahm... er?

https://en.wikipedia.org/wiki/Square-cube_law

It's worth reading and explains why it's so much harder to move things the larger they get.

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

Erm,.... ahm... er?

https://en.wikipedia.org/wiki/Square-cube_law

It's worth reading and explains why it's so much harder to move things the larger they get.

OK, I tried to read it... the maths went right over my head.

But basically.. a ship that is twice the size, does not mean it uses twice the fuel. It would use MORE fuel, because physics?

Which boils down to... as the Sil goes up, the fuel cost goes up MORE?

Not sure if he made it, but http://norsehound.deviantart.com/art/Starship-Wear-and-Tear-508461692 is where the Starship wear and tear rules are. It's basically something for giving ships a bit of character to them, your document reminded me of it, plus its nice for when you introduce a new ship to the players, it's not a fresh off the production line ship and you want to add history and little quirks to its design.

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

Erm,.... ahm... er?

https://en.wikipedia.org/wiki/Square-cube_law

It's worth reading and explains why it's so much harder to move things the larger they get.

OK, I tried to read it... the maths went right over my head.

But basically.. a ship that is twice the size, does not mean it uses twice the fuel. It would use MORE fuel, because physics?

Which boils down to... as the Sil goes up, the fuel cost goes up MORE?

Yes. A ship twice the length in 3 dimensions actually encloses 8 times the area. While the mass of the larger ship isn't going to necessarily be 8 times that of the smaller ship, it will necessarily be much greater than double. Therefore, even with economies of scale, more powerful and more efficient engines, yadda yadda, it's going to use a ton more fuel than the smaller ship to go just as fast (as the energy required for movement is related to MASS not size).

I like the idea of resetting the base cost to 5cr/unit and adding a geometric progression (to the power of) with respect to silhouette.

If you have some time, look up the square/cubed law for the basic reason it should not be linear to fuel the larger ships.

Erm,.... ahm... er?

https://en.wikipedia.org/wiki/Square-cube_law

It's worth reading and explains why it's so much harder to move things the larger they get.

OK, I tried to read it... the maths went right over my head.

But basically.. a ship that is twice the size, does not mean it uses twice the fuel. It would use MORE fuel, because physics?

Which boils down to... as the Sil goes up, the fuel cost goes up MORE?

Yes. A ship twice the length in 3 dimensions actually encloses 8 times the area. While the mass of the larger ship isn't going to necessarily be 8 times that of the smaller ship, it will necessarily be much greater than double. Therefore, even with economies of scale, more powerful and more efficient engines, yadda yadda, it's going to use a ton more fuel than the smaller ship to go just as fast (as the energy required for movement is related to MASS not size).

Allllllrighty then!.... I am sure I still have little idea on the math there,... but I will bow to your less broken brain than mine!

So... on the stipulation that these rules dont cover ships of Sil6 And above (As in my original rules, due to the sheet mass and different drive systems), the suggestion is fuel costs are ... er.. something squared (Sil?) multiplied by... what now?

(Sorry, bit drunk... xmas and all).

The problem I have now, is that this means there is no longer a simple table to work from... you HAVE to do maths on the fly to work out how much fuel is used. (Or I change the Record sheet to have blank spaces to fill in the final numbers for your ship in question). And I add a table to "pre do" the maths in the bulk of the document (Which is alot harder from a layout POV that you think).

Right?

On another note, is anyone interested in joining in with a development of a Version 2 of these rules? I can port the text into google docs where everyone can tag suggestions and work together on a single document (Shays suggestion). If you are, let me know. Any contributions will be credited in the final doc of course