I will try to keep this short. First, you should know I am a high school teacher certified in both the Physical Sciences and in Computer Science. But, I am not trying to get a job here, just want you to know my background. Please feel free to contest my thoughts. I enjoy the discussion. Now then. Straight to the point. It seems to me that any discussion related to mass, volume and hit points should be based in science and therefore, very short. So my question is simple. Why not simply define each of the different materials (i.e. steel, concrete, hardened steel, etc.) by their mass, calculate volume based on the dimensions of each block (object), calculate densities based on their mass and volume and then allow hit points to be a derivative of density. End of discussion. These are easy calculations and based in real science. All you need to define is mass. Now, if you have the mass, volume, and density you can allow players to design their ships however they want. RCS are great, but they make it too easy to cover for a bad design. Some ships should just not fly. You should have to tinker a bit with your design to get the thing in the air, and have some more tinkering to make it fly well. Personally, I like to try and build with as few RCS as possible. However, it seems to me that it should be possible, with the right design, to be able to fly a ship with no RCS. RCS should then only be necessary if you are trying to build way outside of science-based standards. So then, the more strange and non-air-worthy your design, the more RCS you will need. Basically, you should not need to "tweak" anything but your arbitrary mass values assigned to your materials. Everything else is just a calculation.