1. As http://store.steampo...com/app/213030/ does, let the player's mp and health regenerate after each battle, such that the player is not penalized for experimenting with spells. Of course, that does bring its own problems.
I'm actually fairly ok with MP regenerating to full at end of combat. (just like I fully support MPs regenerating progressively in combat). I think magic is a measure of exhaustion of the mind, akin to stamina, and should behave that way in games rather than as a premium resources that costs more to replenish than HPs.
However, I like using HPs as an attrition-based resource. It helps emphasize the journey over the combat. Much like stamina, you have short term energy boost (jumping) which replenishes quickly (you can quickly jump anew even though you've put your entire strength on the first jump) and you also get worn out from global exhaustion over time. HPs help to represent that, forcing you to eat/rest/drink potions along the way.
2. Make the basic attack its own special move that drains stamina. However, if it runs out, then the character can use several turns to rest and gain some stamina.
I've tried that as well. The problem, to me, is that we're tapping into a different problem when doing that.
The RPG combat system is less interactive than action-based combat system. While this gives you time to think things ahead and be more strategic, it can easily fall into a stiuation where there's not enough happening.
Introducing a stamina system, and thus, the possibility that a player may end up having to skip one of its character's turn (or turns) results in reducing the flow of actions. While this may add strategic depth (it could even affect the character's def for example) the reduction of action is a drawback to be reckoned with.
One of the most hated status effect or combat ability is when you are no longer allowed to fight (paralyse, petrification). This is intrinsically interesting from a strategic viewpoint, but extremely frustrating from the player's standpoint. Players in general tend to want to mess up because of themselves, not because of the game. That way, they always know how to improve, and its a good type of frustration that can be channeled through fun (as players improve). If the game puts a hard stop to that,
3. Make it such that attacks can made from combining normal attacks and "buffs", such that the character has to choose between attack, ice attack, fire attack, super ice attack, or whatever, such that the player never has to just choose one when he can choose both.
Is that similar to the idea mentionned earlier?