Is Cheese Equal to Steel?

[David Johnston2]

Originally Posted by AlexanderHowl

I was wondering if it made sense that 1 metric ton of cheese possesses the same HP as 1 metric ton of steel in GURPS?

Yes it does. Bear in mind that a metric ton of cheese is hugely bigger than a metric ton of metal and has no DR.

[Andreas]

No, HP proportional to mass does not give sensible results.

A material with the same material properties as steel, except half the mass wouldn't be much easier to destroy.

Originally Posted by mlangsdorf

I get mozzarella at about 30 lbs per cubic foot - about half the density of water, while steel is about 500 lbs per cubic foot. Cheese should have 16-17 times the volume of steel, not 80.

A 1ft cube of steel has DR 400 and HP 60, while a cube of cheese 2.5 ft on each side with the same weight has DR 1 (maybe) and HP 60. Destroying the huge block of cheese is the work of a couple of seconds with an ax or submachine gun, while destroying the cube of steel requires specialized equipment.

I don't like the numbers on the scaling rules, because I think really large things need more HP then they get in GURPS, but scaling HP with mass produces sensible results if you account for DR.

Originally Posted by whswhs

It depends on whether it's a hard cheese or a soft cheese. A solid block of parmesan could have DR 1 (cutting it with a knife takes some effort!); a block of fresh mozzarella certainly has no DR.

Is that really the case? As I understand it, objects in gurps have DR proportional to their thickness (Basic Set pages 558-559) and such blocks of cheese are very thick.

A 50 inch thick solid block of parmesan having only 1 DR would mean that a 5 inch thick block would only have 0.1 DR (not taking significant effort to cut with a knife).

[Kromm]

The difference is considered to be reflected in DR, not HP. It isn't a flawless model, but it works well enough. Steel has at least 50-60 times the DR of the same thickness of even the hardest cheese! If density (7.75 to 8.05 g/cm³ for steel, ~0.98 g/cm³ for cheese) means the block of steel is ~0.5 times as thick in all dimensions as an equally massive block of cheese, the steel has 25-30 times the absolute DR. Note as well that the DR of cheese is without question ablative, while that of steel certainly is not.

If you want to be picky, you might further remark that cheese is a lot like Unliving organic matter, similar to a zombie or flesh golem. Then you would use the "Unliving/Machine" column of the Object Hit Points Table (p. B558) while continuing to use the "Homogenous/Diffuse" column for steel. That would halve the HP of cheese relative to steel. (On the other hand, gooey cheese might merit Injury Tolerance (Damage Reduction 2) . . .).

So . . . your 8 kg cube o' steel is 10 cm on a side, with DR 196, HP 20 while your 8 kg cube o' cheese is 20 cm on a side, with DR 7*, HP 20 – or optionally only HP 10. (The * means the DR is ablative.)

Again, it isn't perfect, but it's good enough. It looks to me like the biggest problem is ignoring DR.

[Say, it isn't that bad!]

Clearly, cheese is harder to cut than some people think.

After all, this discussion is one big ball of cheese.

*Nods*

[Anthony]

Originally Posted by Kromm

Again, it isn't perfect, but it's good enough. It looks to me like the biggest problem is ignoring DR.

The problem is that DR, in GURPS, is treated as a surface phenomenon, and homogenous objects don't have a hard shell with a soft inside, they're just hard (or soft) all the way through. If you give a chunk of steel enough DR that it's properly hard to destroy in one hit, it's way too difficult to batter it to chunks with multiple hits.

[Mark Skarr]

Originally Posted by Anthony

The problem is that DR, in GURPS, is treated as a surface phenomenon, and homogenous objects don't have a hard shell with a soft inside, they're just hard (or soft) all the way through. If you give a chunk of steel enough DR that it's properly hard to destroy in one hit, it's way too difficult to batter it to chunks with multiple hits.

I have to agree. It's the hammer/eggshell problem: Enough damage to reliably penetrate the DR means an above-average roll will destroy the target.

In general, as an abstraction, I have no problem with a ton of cheese having the same HP as a ton of steel or any other material.

[Tyneras]

You'd probably want HP to follow the current rules, DR to scale up to a maximum amount, either an absolute thickness or % of actual thickness, then start adding IT:DR that scales both with material properties and SM of the target.

All that would be rather complicated tho. Great when GURPS 5.0 comes with an expert NAI bundled with the basic set, not so great for meat brains.

[Anthony]

Originally Posted by Tyneras

You'd probably want HP to follow the current rules, DR to scale up to a maximum amount, either an absolute thickness or % of actual thickness, then start adding IT:DR that scales both with material properties and SM of the target.

Or you could just change HP. Other than breaking the collision rules, which are already pretty broken so no great loss, that's the simplest option.

[Varyon]

Originally Posted by Anthony

Or you could just change HP. Other than breaking the collision rules, which are already pretty broken so no great loss, that's the simplest option.

Having HP dependent on material properties, rather than just mass, could be an option, but things get a bit more complicated when armor divisors come into play. I previously played with this in my Armored Flesh thread (go to the end for the conclusion if you'd prefer to skip the ~4 pages of arguing if DR already did what I was looking for). As steel and the like is harder than flesh to cause any damage at all, it may be appropriate for steel to still have a (reduced) innate DR.