Are there any known combat equations? Things like what offense you need to do max damage against a specific defense? How much defense helps against an given offense? Anything like that. I searched but couldn't find anything.

We came to the conclusion that the damage equation is tanh((randomizer)attack/(5*defense) * damageCap. Somebody had a suggestion for what "randomizer" was, but I don't recall it, and it's not a huge deal, it just randomizes it some. The damageCap is half their deck or (rank+19)/2 for players, or 2.5*rank for NPCs. Thus, you can theoretically only approach the damage cap, though if your attack is very significantly higher you can actually hit it, due to rounding and randomization.

Thanks. Do you know anything about the range for "randomizer"? 0-1, .9-1.1, anything like that? This really does help make sense out of a lot of what I've seen.

What ferris says is correct, lots of peole are still working to find the complete equation to this, complete with all randomizers