Balancing a healing invocation [3.5]

[blackmage]

I am working on a class design that uses something similar to invocations. (similar enough for purposes of this discussion). I would like to have an invocation similar to the Cure Something Wounds line. In the heat of combat, this would of course be excellent, would need to be balanced and tweaked carefully to keep it useful but not invincible.

But what about after combat's over? Such an ability would essentially give infinite healing to the party throughout the day. That...worries me. In all the core classes that have healing, there is a hard daily limit. The philosophy of DnD seems to be that offense can be unlimited, but defense (healing) can be done only a finite amount, and the philosophy makes sense to me. My healing invoker breaks this rule.

So, my two questions to the playground(TL/DR):

1) Is having the whole party's HP topped off between every encounter gamebreaking? Is this kind of unlimited (over time) healing even an issue?

2) If it is an issue, does anyone have any creative thoughts for limiting its use other than the boring X/day?

[Zaydos]

There are a fair number of ways to get at will healing to half health (Touch of Healing, draconic aura of vigor) and they don't upset the balance too much. There is actually a way (Tome of Magic) to get at will cure light wounds with a 5 round recharge time. None of that is really top tier so it shouldn't be too broken.

[Duke of URL]

Steal a page from Dragon Shaman -- the invocation can only heal people to up to 50% of their maximum HP total. They'll get some downtime healing, but nothing game-breaking.

Alternatively, have it not be healing at all, but just temporary HP -- that gives them the effects of being healthier, without the "free healing", at the cost of actions to maintain the HP pool.

Or maybe both -- provide real healing up to 1/2 max HP, and then non-stacking temporary HP on top of it if you exceed that amount.

[Jota]

1) Not really, unless your game has specific design goals to whittle the party down from encounter to encounter (in terms of hit points, rather than wand charges, as per follows). If you're playing by RAW everyone's doing this anyway shortly after first level with wands of lesser vigor.

2) N/A

[blackmage]

So, it sounds like my fear is at least mostly unfounded. As Duke of URL said, what I'm aiming for is an ability that uses the action economy as the cost for keeping health up.

I'm liking the temporary hit points idea, maybe later in the class progression allowing it to be paired with some Fast Healing or the 50% idea. Thanks for the input, all!

[DragoonWraith]

As a Least Invocation, it might be a bit much, maybe. Not even convinced that it would be. It would be kind of like Summon Swarm - a bit better than you should have at level 1, perhaps, but by level 3 it's really not that impressive.

[Zaydos]

A half hp limit cap healing ability is roughly equal a reserve feat taken at Lv 3 so Least would be about right.

A temp hp ability would depend upon how many temp hp it gave.