So I am trying to come up with an idea for healing a character outside of battle, in a JRPG I am designing, that doesn't involve spells or potions or sleeping at an inn or anything too convenient like that (because first-aid kits just laying around dungeons always bothered me a little). Also I don't want a money/currency system in my game. I don't want any items or weapons at all if possible (only abilities, and minions like Pokemon).

My initial idea is to have a mini-game like Pairs, where the player is shown 10 pairs of images for a few seconds, then the pictures are covered up, and the player has to correctly remember the location of the pairs. for every second the player does this under 20 seconds, they are healed 10% of their maximum health points (so if the player completes the mini game in 17 seconds, they are healed 30% of their maximum health).

If I settle on this, I can make it immersion enough to not distract from the game (like have the pictures on the pairs be runes, so representing the character attempting to cast a spell). Anyone can play this game, and attempt it multiple times to heal totally. There is also the possibility of making the mini-game harder later in the story, adding more images or decreasing the time limit.

How do you guys feel about something like that?

This would bug the crap out of me, to be honest. Especially making it harder later in the story (where the combat itself would also be harder, and thus I would need healing more often). It just seems like it would pull me out of the game I'm playing (and RPG), and into some game I don't want to play (matching crap).

Interesting, but I'm not sure I'd see my way clear to doing something like that. Some things to keep in mind here....

First (and perhaps foremost) in the majority of RPG systems (especially JRPGs) "hit points" are merely an abstraction; while they represent wear and tear on a character, what they really do is limit the amount of stuff a character (or party) can be expected to do before having to take a break. They are a resource, like mana, money, energy, etc. This limit can be manifested in a number of ways; for instance, a money sink (i.e. the character needs to buy potions or pay for an inn stay in order to restore health), or a time sink (a player must wait some measure of time to restore health)...this keeps the player from getting somewhere too quickly. It serves both to add a bit of realism but also to maintain pacing for your game play. Keep in mind that hit points do not strictly represent physical damage to a character; they can also represent how tired the character is; consider that a character is (more often than not) able to fight at full capacity even with only one of their 10000000 HP remaining. In fact, many games nowadays tend to refresh your party to full resources between every encounter/battle. In those cases, your HPs are just to contribute to the difficulty curve on a per-event basis.

Why add a mini-game to further pace things out? You are effectively replacing "potions and inns" (which a player most often uses by leveraging resources/gold they gained via game play/combat/exploration) with "pointless busywork" (you just fought a mean battle...now play this card game before you can play the actual game again). If you can make the mini-game super, super fun (I don't see how, but you may) then that's one thing. But any time a game forces me away from its core game play (the reason I play the game at all) into something that's not nearly as fun, I personally get frustrated. I think many players do.

So it would be like having to wait and look how your HP bar slowly fills at like 0.5% per second, but only if you torture your finger constantly for hours by clicking as fast as possible your mousebutton and even that only if you remember all those many random pictures you got shown 1 second?

I thought it was a usability goal nowadays to minimize useless clicks. How about you just refill all HP after every won fight when there are no potions, no healmagic, no anything?

I just don't want it to be too easy to heal, it'll be harder to create tension...

I mean, if an enemy comes long that does damage faster than you can kill him, that's tension right there, whether or not your out-of-combat healing is instant or lengthy. :) But if you want to build a game where you have this feeling of "always on your last hit point", that can make for a good game. Have you played FTL? The number of times I've barely squeezed through a fight with only a few hull points left and every system and room on fire is huge...but it's still a tense situation. (It's also very often on sale on Steam, and cheap anyway.) I get the same experience in XCOM, but that game features perma-death for your soldiers in an environment where it's okay...because you can get more soldiers (though it's not super easy to do so...losing your best troops is really hard). Good games for tension, and both of them have very staggered and slow healing methods. They may help you out.

In addendum, I just saw

An idea I've played with in the past is health that regenerates as you walk, at a rate roughly timed to match up with the damage you take from random encounters. This way you could only stay in a certain area for a certain amount of time, and have your health always be a point of tension, before having to retreat to a safe zone like a town and wait for your health to regenerate (or it could regenerate as soon as you return there).