This is a simple little formula I made up one day. If someone knows what forum would be better for this, feel free to put it there. It's for games like Etrian Odyssey where moves have three main variables: effect, cost, and casting time. For effect, think either damage or healing. For cost, think MP or whatever. Casting time is pretty self-explanatory: think number of turns. (It doesn't work as well for real-time games.) The basic theory is that, while it may appear that a move that costs 5 to deal 10 has the same efficiency as a move that costs 10 to deal 20, the first move is in fact half as efficient, because it takes twice the time for the same effect. (Both moves take one turn in this example.) I use h for effect (think HP), m for cost (think MP), and t for casting time. So for this: h1 = 10, h2 = 20, m1 = 5, m2 = 10, t1 = 1, t2 = 1 CE (comparative efficiency) must equal .5. (If the second move took two turns to cast, they would have equal efficiencies.) Well, I tinkered around a little, and eventually came up with this. I'm completely sure it works. Here's the formula: CE = ((h1/h2)^2 * m2 * t2) / (m1 * t1) I figure it could be useful if you're trying to balance moves with cast times, or trying to make moves that are slightly more efficient than each other, etc. It's probably only gonna be worthwhile in turn-based RPGs, but... dunno. Thought someone might find it interesting. It's harder to quantify things like status effects, but you could probably come up with something if you really wanted. Like make a 50% chance of poison worth 5 or something. So... there it is. Comments?

Yeah, I know it's got limited usefulness, but it has some nonetheless. It can apply to a lot of classic turn-based games, like EO or some Final Fantasy. Granted, you can't build a whole system around it, but it can certainly come in handy.

I didn't know the ES games used something like this. That rules. Morrowind happens to be my favorite game.