So, from what I understand, many industries are interested in resistive sheets but not ones that have the range of resistance that I am interested in – that are comparable with that of a variable resistor over a couple feet. Is this right?
Resistance is resistance. Whether it's a variable resistor or a fixed resistor or a sheet of resistive material. The thing about electronics is that resistances from a small fraction of an Ohm to tens of millions of Ohms are commonly and routinely used. The "best" resistive value depends on what you are doing, what's available (sometimes circumstance dictates what resistance will be used), and what the rest of the circuitry looks like. Without knowing what your design criteria are, it's impossible to even guess at the value you want or need.
Nevertheless, though I haven't been able to find one, it seems to me that a database of the resistive properties of materials may be useful in case such materials are accessible for such things as partitions.
To give an example, the common carbon resistor uses carbon as the resistive part. But, carbon resistors are made in a range from a fraction of an Ohm to 10's of millions of Ohms. The carbon is mixed with non-conductive materials to set the resistance. So yes, you can look for the resistive properties of materials but, there are so many other variables that, unless you are engineering resistors, it's pretty much a waste of time.
You're asking questions that suggest that you've never had training in basic electricity. My first suggestion is to take a class or find an online course to learn about these basics.
Whether the resistance was measured as a function united cubed or united squared may be important – I haven’t researched or thought much about it.
I've never heard the terms about, "function united cubed or united squared". Maybe others here have and can give advice on that.
As for AC, I have tried to use some programs that modeled the flow of electricity. However, they were very complicated and I never got them to work. Can anyone refer me to a model of how AC flows through a sheet? Should I visualize the waves as changing in time or with distance?
Anything involving AC is more complicated than DC. You really do need to get the concepts of DC figured out and work with them for awhile before launching into AC projects.
That you keep wanting to know how the complicated stuff works rather than asking how to start with the most basic concepts and then trying to work up to the more involved ones suggests that you are on a dream quest and the path that you are following will never give you more than a dream.
Until you take the logical steps of learning the basics of electricity and electronics and do some hands-on experimenting, you're just never going to make any progress.
I'm not sure if I'm using the right vocabulary, but what would a model of the wave distribution in the sheet look like if segments of the flow of AC in the sheet were "dampened"?
Resistance isn't "dampened". It's just there. Dampening is accomplished by other circuit actions.
I'm thinking about a wavelength of about one foot on a sheet about one and a half feet by one and a half feet, with one ground, and others with multiple grounds. Could a large enough segment of the wave be dampened or otherwise effected by the base each game piece to produce a unique difference in the way that electricity flowed through the grounds? By unique, I don’t mean unique to each ground but to the electrical characteristics in multiple grounds as compared to one another. Does this make any sense? Would the dimensions of the sheet make a difference in terms of how the AC reacted to the edges of the sheet, or would this even be important to consider?
You're talking about things that happen at UHF and microwave frequencies when you still haven't figured out DC theory. What answer or explanation would you be able to understand?
There are methods that can (and have been) used, with these frequencies to do position finding. Radar for example. But, how do you understand the concepts of something like radar when you don't have simple DC theory and practice under your belt?
As I see it, you have two possible paths. One is to go back to square one and learn electricity and electronics (keeping your goal in mind as you do so) or to keep stabbing in the dark, hoping to find some "magic bullet" that will somehow both sense and resolve what you have in mind.
At this point I really do have to ask if you are even looking for an answer. You don't seem to be interested in the technology of it so much as the esoteric nature of it.