Fantasy Mecha and Giants Armor and Shields

[Kalzazz]

A plate torso of DR 6 provides admirable protection for ST 12 humans, as does a DR 4 shield

Using LTC2 or DF, a SM +4 ST 60 giant or mech can spend a fortune on the same shield or armor

But it will stop a ST 60 sword swing or punch as well as a coat of wet noodles

Am pondering how to deal with this, as I want armored mechs and Giants and such

[Anthony]

Give the SM +4 giant a lifting ST of 110 (or more). Then change the scaling of armor and weapons to:

• Multiply cost and weight by (height/2 yards)^3.
• Multiply DR by (height/2 yards).

That means the suit of plate for a SM+4 (10 yard) giant is 125x weight/cost, but at least it has DR 30, which is respectably effective against a 9d swing.

[RyanW]

A SM +4 giant needs 25 times the metal just to cover himself with the same thickness of armor. Because muscle power scales with cross-section rather than volume, that will also be proportionally just as heavy to the giant as the original was to the human, despite being tinfoil to the giant. Cube-square law hates giants.

[Rysith]

Originally Posted by RyanW

A SM +4 giant needs 25 times the metal just to cover himself with the same thickness of armor. Because muscle power scales with cross-section rather than volume, that will also be proportionally just as heavy to the giant as the original was to the human, despite being tinfoil to the giant. Cube-square law hates giants.

This is fundamentally what you're fighting against, and what you're going to have to think about how to overcome. Step one is to figure out how much DR you want them to have and compute how much it would weigh (using armor scaling and heavy plate), so you have some inputs.

There are a few different options:
- Change the weight scaling of armor for Reasons. Figure out how much you want it to weigh, and adjust the weight scaling until you have what you want based on the 'real' weight. Remember that weight scaling is exponential, so your scaling adjustment will be too. The disadvantage here is that your strong human-scale characters may want to pile on the now-lighter armor as well.

- Change the strength scaling of large creatures, probably (as mentioned by Anthony) by adding lifting strength to avoid adding melee damage. Figure out how much extra strength is needed as a function of SM, and have that be a bonus to being larger. If you allow large player characters, they may find ways to abuse high lifting strength, though.

- Change the damage scaling of large creatures[1] so that large creatures have some inbuilt levels of IT:DR (from Powers) or something similar, and have it apply before DR. DR 6 with IT:DR (5) for SM+4 is effectively 30DR, and also solves the issue that a SM+4 giant with 50-odd HP is taken down by an uncomfortably low number of human-sized arrows to the vitals.

[1] You may want to do this anyway, to prevent your giants from dying of repeated weak attacks

[Anthony]

Originally Posted by RyanW

A SM +4 giant needs 25 times the metal just to cover himself with the same thickness of armor. Because muscle power scales with cross-section rather than volume, that will also be proportionally just as heavy to the giant as the original was to the human, despite being tinfoil to the giant. Cube-square law hates giants.

The solution is to ignore the square/cube law if you're going to have giants.

[Flyndaran]

Physics makes even semi-plausible giants very different from pretty much all fiction.
And Gurps doesn't scale that great not least of all since "man-powered" damage is much greater than is completely realistic.
So if you're going to adjust things anyway, might as well let go and make things how you darn well want them.

[mlangsdorf]

When I did my mecha versus giants game, I I scaled the giants' weight to the cube of their height, and then scaled their strength to the square root of their weight. Basically, A 30' giant was as strong, relative to his weight, as a 6' tall human.

Then I gave them inherent DR so that their punches were about as damaging to each other as a 6' human's punch was to another 6' tall human: this worked out to about 1/5th their ST as DR.

I didn't scale armor weight to the cube of height and then scale armor DR with height, though that would have been a good idea. It makes sense to me that maximum acceptable armor thickness (per DX penalties) is going to scale linearly with size.

That would have worked out:
Massive Giant: 30' Tall, SM+4, ST 160, Base Move 25, DR 35, BL 5120, wears medium plate with DR30 at 7500 lbs (Light Encumbrance). Wields a 30' long sword based on a 3.5" steel rod for sw+35 or thr+22 damage*, which works out to 19d+35 cu or 17+22 im (or 29d cu or 23d+1 im if you convert the dice). If he hit himself with his own sword, he'd do 9d damage past armor or ~48 injury.

The same giant could wear heavy plate, DR45, at 12000 lbs, but that puts him down to Medium encumbrance and a sword will still get through.

Still, unreasonable strong giants wearing thick and heavy armor looks like it works pretty well.

* I prefer to use the scaling rules from Supers p 119-121, but I suspect you'd get similar numbers from Low Tech.