That's kind of the opposite to me, I love tinkering around with stuff like this, but I actually get bored of programming quite fast - programming is just a way to get my ideas working really.
Truth is, what you're talking about is a very complicated issue. Most RPG's use similar systems because that's what works, and in my opinion, because they're lacking imagination. You're right though, the guts of the program are absolutely vital to the success of the game, and if you don't get this part right, the rest will fail. As an example, I'm currently working on a football (Soccer) game. It's absolutely crucial that the match itself works correctly and uses the player's skills to generate a convincing result - otherwise the rest of the game will fail regardless.
Unfortunately I don't think we can help too much because the problem is too broad. What sort of numbers are you using for your characters and items? If it's very similar to an existing game such as D&D or WoW then you could probably just try to mimic their results. Personally I'd go for a whole new system, but that would be ambitious.
Truth is, what you're talking about is a very complicated issue. Most RPG's use similar systems because that's what works, and in my opinion, because they're lacking imagination. You're right though, the guts of the program are absolutely vital to the success of the game, and if you don't get this part right, the rest will fail. As an example, I'm currently working on a football (Soccer) game. It's absolutely crucial that the match itself works correctly and uses the player's skills to generate a convincing result - otherwise the rest of the game will fail regardless.
Unfortunately I don't think we can help too much because the problem is too broad. What sort of numbers are you using for your characters and items? If it's very similar to an existing game such as D&D or WoW then you could probably just try to mimic their results. Personally I'd go for a whole new system, but that would be ambitious.