Robots as Spaceships: Battlesuits Revisited

Earlier, I wrote a simple method for making custom sized powered armor in Gurps:

After you build the armor with the right DR, add 50% more weight to the armor, and you have a suit of powered armor. Look up the strength based on its weight here

Basing the cost of the system on the additional weight is fine for most of the armors given in those pyramid articles. The "true" cost is $70 per pound of added weight with no leg or arm cost reductions.

The problem is... this system doesn't scale properly. Armor up to about 150 lbs worked out right, but once that was passed, the battlesuits got better and better for their weight class, and posted incredible DR's, like a half ton suit of armor giving almost 450 DR at TL10!

I noticed that this weight of 150 lbs was the point at which the weight of the armor began to be larger than the weight of the wearer, and calculated a new formula for battlesuits weighing 150 lbs or more (which to be fair, is most of them). 

DR = Weight^(1/3) x 3.5 x TL DR Factor

The TL DR Factor is 3 DR at TL 9, 5 DR at TL 10, and 7 DR at TL 11*. Cost per pound of the armor is $1 times its base cost. 

*This is the same number as for 7.5 lbs of armor talked about in the article being updated.

With this new system, the battlesuits outperform the walkers in terms of DR until about the 1.5 ton mark... which is perhaps a bit higher than we wanted, but isn't a bad number.