Just my 2 cents:
pawsplay said:
Let's take rules zero to the curb and stomp it. Try this: dragonfire adept, feat that gives them extra uses of an ability (since, after all, at will is virtually the same thing as 14,400/day) plus a quicken ability and maximize breath.
So the maximize the breath in round one, and quicken it. Now, they still have an action left. Ordinarily, they would have to wait several rounds, but they can now use their breath attack an additional time thanks to a feat. So they do, and breath again, and maximize it again. So in round one, they launch two maximized breaths.
Lets see...
The breath of the dragonfire adept is usable at will as a standard action -> 1/round with recharge time of 0 rounds. The description of the ability doesn't describe it as an invocation or spell-like ability, thus I would rule it as a supernatural ability, just like any other breath weapons I can recall.
I disagree with you about several things here:
1-Maximize Breath specifically says that you must use the breath weapon as full-round action, thus, you can't use it more than once in any given round.
2-If the breath is a supernatural ability, that means that you can't use it with Quicken Spell-Like Ability and the Quicken Breath specifically says that you can't combine it with Maximize Breath.
3-Even if the Maximized Breath counts as a Spell-Like Ability, thus allowing you to use it as a free action via Quicken Spell-Like Ability, and supposing that you allow the Quicken effect to override the "Full round action" thingy, the +3 rounds delay kicks in as soon as you spit the first Maximized Breath in any given round. Thanks to the delays you just can't breath (the word "cast" doesnt quite feel right) more than 1 "metabreathed breath" (did that even make sense??) in any given round.
4-The feats that give extra uses for an ability specifically say that the ability must have a limited amount of uses per day. (otherwise the breath of a True Dragon would have something between 2880 and 7200 uses per day and I really don't know how you would handle the extra uses.)
In fact, I don't find Maximize or Quicken breath that bad. Enlarge Breath, Lingering Breath and Clinging Breath, however, are absolutely broken. Why? Well, RAW, there's nothing that keeps you (or any True Dragon with proper feats) from belching a truly epic cone of fire that extends 5'000,000 gazillion of light years into deep space and will stay there for a friggin' millenium as long as you don't mind ever using your breath weapon again. I simply can't understand why Heighten Breath is the only one that puts a cap on the feat to avoid this kind of sillyness.
To prevent this, I would home rule that all metabreath feats that stack with themselves may be stacked up to a maximum of times equal to the "breather's" Con bonus.
Thinking about it, I feel that the delay drawback for the metabreaths begins to crack apart on high level play, as soon as you begin to stack 3 or more effects on the same breath. I don't believe that warlock-like classes were supposed to be able to get unlimited novas.
Picture it:
First round-> entangling, maximized, heightened, split, clinging, discorporating breath of bahamut (that's double damage + disintegration for you) FTW!!!
The fact that you must wait 15 rounds before using your breath weapon again doesn't feels as a particularly balancing drawback.
If you don't want to disallow the feats, I would recommend you to find another way to control the overstacking. (Put a limit to the amount of delay that you can add to a breath, or something like that.)
