Are you talking about RPG video games for platform systems? Not trying to be a "rules lawyer" (heh--old inside joke to RPGers
) but I find a big difference between
1) the classic pen & paper RPGs (like D&D) where the interaction is between real live people sitting together,
2) computer-based RPGs, which are usually just 1-person affairs that use a classic mathematical RPG-based engine to make decisions, process outcomes, guide pre-set conversations, etc,
3) computer-based multiplayer on-line RPGs (like World of Warcraft) and
4) platform based RPGs.
I'm old school, so I prefer 1 & 2, especially when the computer-based game can be adapted for small party on-line play (like the Baldurs Gate & Neverwinter Night series.)
Combat is a bit different for each of those, but should be based on some mathematical or statistical formula. Values are given to attack and defend, and then dice or some other random number generator is used to help calculate a probability value that indicates a chance to hit. Most video games just have enhanced graphics to demonstrate the outcome of that equation (hits, misses, critical hits, etc.)
As I am rambling, it occured to me that you might be asking something entirely different.
So I'm just gonna stop here and say: I've been a big RPG fan for more than 20 years, and I've never played any of the Final Fantasy series!