Jump to content

Adjusting SIZ


Atgxtg

Recommended Posts

To quote myself from the BRP flaws thread:

The fact that the SIZ scale is not linear would not irritate me, but that it does

not distinguish between "low weight / high volume" and "high weight / low vo-

lume" really does. This way both the dirigible on BGB page 271 and the locomo-

tive on BGB page 277 have SIZ 100, and to me this does not make any sense.

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

I got a solution for both of these problems.

First off, if the SIZ table keep the same progression we could get soem sort of consistency between values. It would also lets up use the table for some math shortcuts. Like knowing that if we triple the mass we add +13 SIZ and so on.For example:

Mass SIZ

x1.5 +4

x2 +8

x2.5 +11

x3 +13

x4 +16

x5 +19

x6 +21

x7 +23

x8 +24

x9 +25

x10 +26

Secondly, we could differente between SIZ/Volume and SIZ/Mass. Then we could list VOL offsets for a given density. For instance, using the +8 doubling progression, we could know that a steel cube that is 8 times as dense as water would have a mass 24 points higher for it's volume than a cube of water.

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

Link to comment
Share on other sites

I like the idea of separating size from mass; but how to do that mechanically would require some thought. Also, to what benefit is adding the additional complexity?

There is not a "mechanical equivalents" system in BRP. "Does this work for this setting/game and is it fun" seems to be the most significant measure. What is an attribute point worth versus A skill point? Looking at the creatures in BRP versus Legend, what are Traits worth compared to say an Attribute point? What about the BRP Angel's ability to fly versus a fly trait?

Without any system in place, making a creature or vehicle in BRP becomes a simple exercise in "what do I want this creature or vehicle to do?" Maybe it just works better that way?

Trentin C Bergeron

Bard, Dreamer & RPG Enthusiast

My Blog | My Worlds

Link to comment
Share on other sites

Without any system in place, making a creature or vehicle in BRP becomes a simple exercise in "what do I want this creature or vehicle to do?" Maybe it just works better that way?

It works as long as there is no situation where characters can build vehicles

or one has to deal with vehicles designed by different people. For example, in

my science fiction campaigns the characters with the relevant skills (Enginee-

ring, Science, Technology ...) can design and build devices and vehicles, and

without a common and well defined framework for what is possible with the

technology of the setting this would soon run into problems.

Edit.: Just imagine a magic system with no other framework than "What do

I want this spell to do ?" - no range, area, endurance or any other data for

the spell. I doubt that magic user players would enjoy that.

Edited by rust

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

I like the idea of separating size from mass; but how to do that mechanically would require some thought.

Not much. The easiest way would be to simply make SIZ equal to the volume of an object and that MAS is the mass of the object. I use MAS here instead of weight, so we don7t get into problems with Sci-Fi settings.

If we take a standard SIZ 13 person as the standard, we can say that they are SIZ 13 and MAS 13, and use that for the basic equality. If we assume that people are about as desnse as water, with a specfic gravity of 1, we can determine the volume of any other object by multipling it's SIZ by it density and looking up the equivalent mass.

For instance, lets say we are making a solid gold statue of a SIZ 16 guy.

Gold has asg of 19.3, so the statue should have a mass 19.3 times than of water. SIZ 16 is about 100kg, so our gold statue would have a mass of 1930 kg, or SIZ 49.

So we know that the MAS of a gold object would be 33 points higher than it's SIZ. That is a constant and would hold true for any gold object, or any SIZ.

Just as long as the table was consistent.

Also, to what benefit is adding the additional complexity?

Mostly the benefit of modifiers for hitting big things, or effects of proper MAS for falling damage purposes. For instance, a 100 ton airship would be a lot bigger than a 100 ton locomotive. Probably around a thousand times the size. Makingit much easier to hit, and much harder to park.

Plus, we know know that a guy with STR 18 doesn't have a chance of picking of a life sized gold statue of a SIZ 16 guy.

Edited by Atgxtg

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

Link to comment
Share on other sites

Mostly the benefit of modifiers for hitting big things, or effects of proper MAS for falling damage purposes. For instance, a 100 ton airship would be a lot bigger than a 100 ton locomotive. Probably around a thousand times the size. Makingit much easier to hit, and much harder to park.

For example, the Hindenberg is actually about the same length and volume of the Japanese battleship Yamato, but the Yamato definitely weighs significantly more.

Plus, we know know that a guy with STR 18 doesn't have a chance of picking of a life sized gold statue of a SIZ 16 guy.

Good point.

Ian

Link to comment
Share on other sites

Same complaint as in other threads. SIZ for human-scale characters is pretty consistent, going from a 5'2" petite blond to an 8-foot hulking kinda guy. Once one gets beyond those dimensions, a character or creature's height doesn't necessarily scale along with its mass, forcing one to guess its mass to determine SIZ. I'd like a consistent height scale so I could easily SIZ Goliath, Tars Tarkas, King Kong, and Godzilla the same as I do human characters. Also, going the other direction: Donald Duck (or Howard), Reepicheep, or Basil of Baker Street via a consistent scale. Atgxtg may be up on all the height/mass/body density ratios, but I'm not.

Link to comment
Share on other sites

Well, to the extent that all the stats are abstracts I'd be quite happy with the following:

three tables

1] length

2] height

3] weight

the average of the three being the SIZ stat. Not really that complicated, if you can't add three numbers together and divide by three to get an average you've got problems.

Link to comment
Share on other sites

OK, I guess at this point I can dredge up my old formula that takes STR, mass, and height (in meters - and by height I mean longest distance along an axis) and calculate SIZ. Maybe I can rework it bit to give it to scale it properly. I think it was discussed in this forum before, and I gave some example calculations ...

Ahh - found the discussion:

http://basicroleplaying.com/showthread.php/702-The-Chaosium-s-BRP-Size-Table-and-Superworld

I was able to wrestle with my formula and given mass, height and STR (some values had to be guessed at) and came up with what I thought were reasonable SIZ values for an average human woman, a D&D chimera, a skeleton, and Dhar Corondon, Corastin, Croid and Bronth (all from Jorune).

Ian

Edited by vagabond
Link to comment
Share on other sites

I don't think you have to abandon SIZ altogether. But there are times when mass or dimensions are much more useful. For example: my backpack holds a certain volume, but I can only carry a certain mass. So if I fill my pack with lead, I can't lift it; if I fill it with feathers, I can lift it with one hand. I don't see the use of giving the pack, the lead, or the feathers a SIZ value.

When we care about things like lifting, we just need to have a table for how much mass a certain STR (or STR + SIZ or whatever) can lift and carry. For extremely large things like a dirigible, battleship, blue whale, etc., I don't think SIZ really does any work for us. So my suggestion is just to ignore SIZ when what you really want to know is dimensions (what fits) or mass (how much can I lift). SIZ works for a rough approximation of the difference between a man and a cow, a big man and a shrimpy man, and so forth. It works as an approximation like an opening is SIZ 10, so a SIZ 13 person will have a tough time getting through and that difficulty is represented on the resistance table. But do we need to know if something is SIZ 640 because an opening is only SIZ 600?

So I don't see the need for giving a very large object a SIZ. But maybe someone else can give an example of when knowing something like a certain ship is SIZ 350 rather than SIZ 325 matters.

My avatar is the personal glyph of Siyaj K'ak' a.k.a. "Smoking Frog."

Link to comment
Share on other sites

So I don't see the need for giving a very large object a SIZ. But maybe someone else can give an example of when knowing something like a certain ship is SIZ 350 rather than SIZ 325 matters.

According to BGB page 277 there is a correlation between an object's SIZ and

its damage resistance ("an average object has hit points roughly equivalent to

its SIZ"), but in my view this is also not very convincing. As has been mentio-

ned, the zeppelin "Hindenburg" and the battleship "Yamato" have approximately

the same SIZ, but I am fairly certain that they do not have the same number of

hit points, and the rule of thumb "SIZ = Hit Points" actually works for very few

real world examples.

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

According to BGB page 277 there is a correlation between an object's SIZ and

its damage resistance ("an average object has hit points roughly equivalent to

its SIZ"), but in my view this is also not very convincing. As has been mentio-

ned, the zeppelin "Hindenburg" and the battleship "Yamato" have approximately

the same SIZ, but I am fairly certain that they do not have the same number of

hit points, and the rule of thumb "SIZ = Hit Points" actually works for very few

real world examples.

Yes, which is why the (SIZ + STR)/2 average works out nicer. The Yamato would probably have a much higher STR than the Hindenberg. And, if you modify SIZ to either be lreative to mass, volume and STR, or more closely aligned with mass, the standard HP formula would probably work out nicer since the Yamato would have a higher SIZ in both cases.

Ian

Link to comment
Share on other sites

Yes, which is why the (SIZ + STR)/2 average works out nicer. The Yamato would probably have a much higher STR than the Hindenberg. And, if you modify SIZ to either be lreative to mass, volume and STR, or more closely aligned with mass, the standard HP formula would probably work out nicer since the Yamato would have a higher SIZ in both cases.

I am not convinced that STR is useful in determining the hit points of a vehicle.

When I give a vehicle a more powerful engine this does not necessarily increase

its damage resistance - even a Hindenburg with ramjet engines more powerful

than the diesel engines of the Yamato would have less hit points than the battle-

ship.

In my view everything but the dimensions and the mass of the vehicle (or any

other object, many have no STR anyway) could be deleted from the equation.

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

I am not convinced that STR is useful in determining the hit points of a vehicle.

When I give a vehicle a more powerful engine this does not necessarily increase

its damage resistance - even a Hindenburg with ramjet engines more powerful

than the diesel engines of the Yamato would have less hit points than the battle-

ship.

In my view everything but the dimensions and the mass of the vehicle (or any

other object, many have no STR anyway) could be deleted from the equation.

The Hindenberg had 4 × Daimler-Benz DB 602 diesel engines producing 890 kW (1200 hp) each, for a total of 3560 kW (4800 HP).

The Yamato had 4 steam turbines producing a total of 111,855 kW (150,000 shaft horsepower).

And, you assume a vehicle's STR is solely determined by the output of its power plant. I do not believe that to be the case.

Ian

Link to comment
Share on other sites

The Hindenberg had ...

True, but what I did mean was that even a Hindenburg retrofitted with ramjets

more powerful than the Yamato's diesel engines would have less hit points than

the battleship.

Edit.: But if you do not like that example, take two otherwise identical ships, one

with a diesel engine of 10,000 kW, the other with a diesel engine of 20,000 kW.

These two ships should have different STR, but I see no reason to also give them

different hit points.

And, you assume a vehicle's STR is solely determined by the output of its power plant. I do not believe that to be the case.

As far as I can see the BRP system does not offer useful data on other potential

variables, like structure or material, to determine the STR of vehicles or other ob-

jects.

Edited by rust

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

I'm not convinced that vehicles should have "hit points" unless they are living creatures, like the Vorlon ship in B5.

The Yamato's ability to absorb damage comes from its armor and the distribution of various systems and components. It's hard to knock-out one thing that renders the ship inoperable. The Hindenburg on the other hand has no armor at all and would be easily shot down by puncturing enough of its gas cells or with some luck just setting it aflame. If you're going to model vehicles like this, I think you need to have a somewhat sophisticated system of damage: what sort of weapons can get through what part of the ship, and what damage to various systems can do. The famous demise of the Bismark is food for thought: crippling one system (steering) might be easier than reducing the hull to Swiss cheese. Of course the USS Arizona and HMS Hood are examples of one or a few explosives penetrating the right place and blowing the ship up instantly.

My avatar is the personal glyph of Siyaj K'ak' a.k.a. "Smoking Frog."

Link to comment
Share on other sites

True, but what I did mean was that even a Hindenburg retrofitted with ramjets

more powerful than the Yamato's diesel engines would have less hit points than

the battleship.

Well, besides the fact that the Hindenburg couldn't handle that much power without ripping itself apart, you still have the fact that the Yamato's mass (and thus SIZ) would be exponentially (at least) higher than the Hindenburg. And, you would have to figure out how to equate HP to STR. I think you would find that using some sort of reasonable scale, the Yamato's SIZ (mass) advantage would sufficiently outweigh (no pun intended) the Hindenburg's fictional ramjet STR.

Edit.: But if you do not like that example, take two otherwise identical ships, one

with a diesel engine of 10,000 kW, the other with a diesel engine of 20,000 kW.

These two ships should have different STR, but I see no reason to also give them

different hit points.

Again, you need to figure out the proper power to STR conversion, and see how much of an effect it has on the STR+SIZ average.

As far as I can see the BRP system does not offer useful data on other potential

variables, like structure or material, to determine the STR of vehicles or other ob-

jects.

No it doesn't, which is something that needs addressing. In a vehicle's case, STR would be structure points - some combination of STR(ength) and CON. Something to measure the relative sturdiness and power of the vehicle. So, while the fictional ramjets on the Hindenburg may have high power, it is still nowhere near as sturdy as the Yamato.

Ian

Link to comment
Share on other sites

OK, I guess at this point I can dredge up my old formula that takes STR, mass, and height (in meters - and by height I mean longest distance along an axis) and calculate SIZ. Maybe I can rework it bit to give it to scale it properly. I think it was discussed in this forum before, and I gave some example calculations ...

Ahh - found the discussion:

http://basicroleplaying.com/showthread.php/702-The-Chaosium-s-BRP-Size-Table-and-Superworld

I was able to wrestle with my formula and given mass, height and STR (some values had to be guessed at) and came up with what I thought were reasonable SIZ values for an average human woman, a D&D chimera, a skeleton, and Dhar Corondon, Corastin, Croid and Bronth (all from Jorune).

Ian

And, playing with the formula a little (since I have no idea what the STR of the battleship Yamato would be, so I worked with partial volume knowing length, beam and draft), I was able to get the Yamato's SIZ as 788.

Figuring out the Hindenburg's SIZ is a problem - the structure weighed about 129.9 tons (~117.82 mt), but that beast was huge dimensionally (245m long, 41.15 m wide at the widest point).

Ian

Link to comment
Share on other sites

I'm not convinced that vehicles should have "hit points" unless they are living creatures, like the Vorlon ship in B5.

For my setting's vehicles I normally use only armor and location. Once a weapon

is powerful enough to penetrate the armor of a location, this location is damaged

and no longer functional. For example, if a weapon hits a ship's bridge and pene-

trates the armor there, the bridge is damaged and can no longer be used until it

is repaired. In my view this works quite well for modern and futuristic heavy wea-

pons, which usually do a lot of "area" damage when they are able to penetrate

armor, so counting individual hit points does not seem necessary.

"Mind like parachute, function only when open."

(Charlie Chan)

Link to comment
Share on other sites

Same complaint as in other threads. SIZ for human-scale characters is pretty consistent, going from a 5'2" petite blond to an 8-foot hulking kinda guy. Once one gets beyond those dimensions, a character or creature's height doesn't necessarily scale along with its mass, [/

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

Link to comment
Share on other sites

For my setting's vehicles I normally use only armor and location. Once a weapon

is powerful enough to penetrate the armor of a location, this location is damaged

and no longer functional. For example, if a weapon hits a ship's bridge and pene-

trates the armor there, the bridge is damaged and can no longer be used until it

is repaired. In my view this works quite well for modern and futuristic heavy wea-

pons, which usually do a lot of "area" damage when they are able to penetrate

armor, so counting individual hit points does not seem necessary.

I can see some problems with this approach. For starters a biug vehicle, like an airship could be easily penetrated (it's skin is calf intensitines), and even with the heavy vbehicles it doesn't hold up. Consider firing a M1A1 tank at a Iowa class Battleship., 1km away The 120mm ADFSDSDU round will easily penatrate the 310mm belt armor, and possibly come out the other side! Yet the M! would probably run out of ammo before it could sink the battleship.

IMO, hit points make a lot of sense, and basing them off of the SIZ/mass of the vehicle is probably the best solution for BRP. After all, the ability to soak damage is a function of how much mass one has to take hit. Tanks and battleship can take more punishment becuase they are made of denser material, and often face hardened.

STR I see as being the power/amount of force '(yeah the two terms aren't the same, but close enough for BRP) the vehicle can exert. Of coruse, the engines on something like the Yamato will big big and have a lot of mass to provide all that power, and in turn will increase the SIZ/Mass and the hit point.

I could see doing HP by location for vehicles, but it can be a bit problematic since it is hard to hit the lleft side of a tank, when shooting from the right.

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

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...