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BRP SIZ Table(Metric Corrected)


Atgxtg

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Here is a corrected version of the BRP SIZ table.

What's wrong with the table in the BRP rulebook?

All of the metric values given in tons are about half of what they should be. Apparently whoever did the table originally, assumed that since 1 kg = 2.2 pounds, then 1 metric ton = 2.2 English short tons, when in fact 1 metric ton is about 1.1 short tons.

brpsiztablemetriccorrec.png

Chaos stalks my world, but she's a big girl and can take of herself.

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The problem is: what is the correct value in the original table? The metric tons or the british tons?

The British tons. Three reasons:

1) The British values progress normally, while the metric values for SIZ 64 (6455-7000 kg) and SIZ 72 (6.4-7 mt) are basically the same. So either every SIZ value between 64 and 72 has the same mass or the metric values are off.

2) The rules specially state that for SIZ 330+ the SIZ value is 1/10th the weight in short tons. The metric value listed, 1500 metric tons is about half what it should be to correlate with 3300 short tons.

3) I asked Jason, and he said to assume the English measurements are correct.

Chaos stalks my world, but she's a big girl and can take of herself.

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3) I asked Jason, and he said to assume the English measurements are correct.

Well, point 3) was enough to persuade me :lol:

I will be eternally grateful to you for this, atgxtg. I will be running a mecha game at Tentacles, and the SIZ values in the mecha range are really important for that kind of game. I'll have to rewrite all the stats, but it is worth doing it.

Proud member of the Evil CompetitionTM

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Well, point 3) was enough to persuade me :lol:
:D

I will be eternally grateful to you for this, atgxtg. I will be running a mecha game at Tentacles, and the SIZ values in the mecha range are really important for that kind of game. I'll have to rewrite all the stats, but it is worth doing it.

Thanks. Sorry about the rewrite. :(

If it is any consolation, II'm in the same boat. You see, the way I spotted the error. I was working on my vhecile and spaceship rules and was getting the "wrong" speed answers when I switched from metric to English (smaller SISZ scores meant faster vehciles). I ended up with a headache at 3:30 AM wondering if I had forgotten how to do math. It wasn't unitl the next day that I looked closely at the table, then I pulled out a copy of Call of Cthulhu and discovered it had the same bug, and then asked someone else to double check it for me, as I began to doubt if I knew what a ton/tonne was.

If it would help, I have a table with values for all SIZ scores from 1 up to 330. I need to tweak it a little to match up perfectly, but it is fairly close (within a lb/kg/ton/mt or two).

If you want, I could email it to you, and even add in conversion from old metric SIZ to new.

Least I could do, since I messed up all your mecha. :o

Chaos stalks my world, but she's a big girl and can take of herself.

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Here is a corrected version of the BRP SIZ table.

Thank you very much indeed. :)

Until now I have only used the table for creatures, so I did not encounter

the problem, but I will soon need stats for the various vehicles of my new

setting, and then I would have walked into that trap.

You really saved me a lot of time, because the contradictions between the

already known size of the vehicles and the mass they should have according

to the flawed table would have caused me to take the vehicles back to the

drawing board.

Good that you found and solved the problem. :thumb:

"Mind like parachute, function only when open."

(Charlie Chan)

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If it would help, I have a table with values for all SIZ scores from 1 up to 330. I need to tweak it a little to match up perfectly, but it is fairly close (within a lb/kg/ton/mt or two).

If you want, I could email it to you, and even add in conversion from old metric SIZ to new.

Why not stick it up in the downloads section under Resources ? It might come in handy for lots of folk

Edited by Agentorange
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Thanks for the praise, but...

I spotted a couple of errors that I need to fix.

1) SIZ 3 should be 38-51 pounds not 38-54.:o

2) SIZ 248 should be SIZ 240 to match with the table in thew BRP rulebook. However, according to the mathematical progression used in the table, SIZ 235 is probably the correct SIZ. I got to check with Jason on that and on a couple of things I discovered while working on the Expanded SIZ table that covers everything up to SIZ 330. THe table in the BRP book uses a increasing progression from SIZ 96 up to around 272 or so.

SIZ 96-103 is +1 ton per SIZ point

104-111 is +2 tons per SIZ point

112-119 is +3 tons per SIZ point

...and so on up to over +23 tons per SIZ point.

Unfortunately, the table breaks with the progression in a couple of spots that I believe are typos rather than intentional changes. For example SIZ 232 is listed as 1220 tons, only 36 tons more than the value for SIZ 224,but according to the mathematical progression used, it should probably be 1320 tons. 1320 would fit the progression perfectly (+16 tons per SIZ at that point), and smooth out the SIZ values from 224 to 232. But it would also throw the values over 232 off by 100 tons up to 330.

Give me a little time to work out the expanded SIZ table before we talk wiki.

Chaos stalks my world, but she's a big girl and can take of herself.

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Your contribution is priceless, atgxtg. If you do not mind, I will also put the revised table in our upcoming Mecha supplement :D

IF you can, please give me a little time to finalize the weights and masses for SIZ 225+.

If it would help, I could put up my speed formula from my vehicle design rules. I'm trying to get it to the point where you can calculate a vehicles Move rating by it engine/powerplant rating, mass, and vehicle type (ground vehicle, aircraft, watercraft, submersible craft, spacecraft).

And just to show that I'm doing something, here is a peak at how the Expanded SIZ table is looking. Entries in blue are table from the BRP rulebook, the rest from RQ3 (up to SIZ 88) or worked out by me using the increasing progression that seems to fit the data points from SIZ 96 to 224 (and possibly beyond).

expandedsiztableteaser.png

Chaos stalks my world, but she's a big girl and can take of herself.

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And just to show that I'm doing something, here is a peak at how the Expanded SIZ table is looking. Entries in blue are table from the BRP rulebook, the rest from RQ3 (up to SIZ 88) or worked out by me using the increasing progression that seems to fit the data points from SIZ 96 to 224 (and possibly beyond).

The RQ3 size table is pretty odd and seems illogical. I have a pdf I wrote on SIZ a year or so ago.

Have you given any thought on redoing the entire table?

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The RQ3 size table is pretty odd and seems illogical. I have a pdf I wrote on SIZ a year or so ago.

I find the RQ3 table, from SIZ 7 thru to SIZ 90, barring a typo or two, very logical. Each doubling of mass is worth +8 SIZ. You can even add with it. Two SIZ 30 objects = SIZ 38; four are SIZ 46 and so on. It's even possible to add different STRs together to get a total. It just not easy or intuitive. Few people can do power equations like 2^(1/8) in their head. That each SIZ is 9.05% larger than the previous one isn't easy math to do in your head.

Have you given any thought on redoing the entire table?

Yeah, i have. In fact I sort of did before BRP was release. IF I were to try and redo it from scratch I would probably:

1) Keep a doubling formula but try to use a fixed increase like +1 SIZ = Mass x1.1. That is almost a x2 mass= +7 STR.

2) I'd use the same formula at the high end too. It would help with big vehicles, like space cruisers, and make it easier to calculate SIZ values with a fomula rather than looking it up on a table.

3) A constant formula would make it easy to work out vehicle speeds using a STR-SIZ formula. (That's how I got into this in the first place).

But, my goal, at least for now is to work with the table as is, limiting my changes to correcting typos, imperial/metric conversion errors, and what I think are math or cut & paste errors. That way people can use the table and know that the values are consistent in both systems of measurement. If I did a new table, people couldn't benefit for the math fixes without taking any problems that might arise from a whole new table.

Besides, I can always try to "reinvent the wheel" later.

Chaos stalks my world, but she's a big girl and can take of herself.

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Okay, here it is, the new, and (hopefully) improved SIZ table. It covers all SIZ scores from 1 to 330 (at that point +1 SIZ is +100 short tons).

I like to thank Jason for letting me run with this--and giving me the change to shoot myself in the foot. :D Anything that's messed up on this is my own fault.

Numbers with a Blue Background: Are values copied directly from the table in the BRP rulebook. At least for the English values. Metric values have been adjusted to match up with the English values. For example 220 short tons now corresponds to 200 metric tons, and both are SIZ 136.

Numbers with an Orange Background: Are values that I altered from the BRP table, based on the ideas that 1220 tons for SIZ 232 was a typo, and that the increasing progression used before and after it was meant to be followed up to the high 200s, and only departed from to have SIZ 330 match up with 330o short tons.

Number is Red: Are problem spots that I want to look at again.

Problems, errors, etc: A few values on the "cusp" might not match perfectly between English and metric due to rounding and a desire to try and avoid overlapping masses for values given in kg.

Once the table switches to tons, there is overlapping, as the values round to one decimal place (or none). I could eliminate this by working the values out to another decimal place, if people think I should.

I'm sure I left a typo or two or even a error on this table somewhere. I'm going to look it over and check for errors again, but no doubt someone here will spot something stupid, obvious and embarrassing before I do. :o But, the sooner it comes to my attention the sooner I can fix it.

So let me know how it looks. Feedback is always (well, almost always:D) appreciated.

exapandedandadjustedsiz.png

Edited by Atgxtg

Chaos stalks my world, but she's a big girl and can take of herself.

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There are a lot of numbers, which is good.

It is a table so I can look up a SIZ to give me a weight, which is good.

It roughly agrees with the rule of thumb of SIZ = weight in stones for normal sized people, except for below SIZ 5 and above SIZ 17, which is good.

Why is Short Tons shown as Weight and metric tonnes shown as Mass?

It only goes up to SIZ 300, which is bad. What if I have a SIZ 310 starship, giant or mecha?

Is there an underlying formula or is it handcrafted?

Having it as a spreadsheet would be good.

Enough comments? :)

Edited by soltakss

Simon Phipp - Caldmore Chameleon - Wallowing in my elitism since 1982. Many Systems, One Family. Just a fanboy. 

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Hmm, no comments.

I wonder if that is good or bad.:confused:

Good, in my case. :)

I am currently waiting for a Mongoose Traveller supplement that is

announced for July, Civilian Vehicles, which I plan to use for the

(re-) design of almost all of the vehicles (air, sea and underwater)

of my current Anuira water world setting.

Once this is done, I will convert the data of these vehicles into the

BRP system - and this is where your table will have its opportunity

to shine. ;)

"Mind like parachute, function only when open."

(Charlie Chan)

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Why is Short Tons shown as Weight and metric tonnes shown as Mass?

Differences between the Imperial (English) and SI (Metric) Standards. Pounds are a unit of weight, where as kilograms are a unit of mass. Now for most purposes you can treat kilograms as a unit of weight, as in most cases characters are in 1G gravity.

But, this isn't always true. For example, if someone was running a Sci-Fi campaign and the PCs had problems while doing something outside their space ship (EVA), their masses would be the about the same, but their weights would be about zero.

This will be important for spaceship design, since the engines need to move the mass, not the weight. Otherwise, any engine could move any ship at and infinite (well undefined) velocity (divide by zero, error).

Chaos stalks my world, but she's a big girl and can take of herself.

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  • 2 weeks later...

I have rewritten the mecha stats for next Sunday's game and they were not disrupted by your modifications. I think they are an improvement over the standard table.

:D

Glad to hear, uh, read it.

BTW, In the threat I started for vehicles/cars, I did a table that correlated horsepower and kilowatts to STR using 1 hp =108 pounds/1 kW- 65kg and the SIZ table for correlation. I might tweak it a little, but It seems okay for most of the stuff I've tried it with, including some mecha designs of my own and even one suit of powered armor, although I really had to use torque instead of power for truck STR scores (otherwise those 212hp, 1500 ft-lb big rigs end up as strong as a 4 door sedan).

I'm curious if you did something similar for your mecha write ups. A lot of the anime series give out technical specs for the mecha in real terms that could be correlated that way.

Chaos stalks my world, but she's a big girl and can take of herself.

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