"Guys, hold 'em off for the next 5 rounds or so!"

[Amechra]

Elder Giant Magic: For each round that I delay (up to 3 rounds), I get a +1 to CL.
Meticulous Magical Methods (Flaw): I'm flat-footed in any round in which I cast a spell, and I can't cast defensively.
Ponderous Spellcaster (Flaw): My casting times are doubled; I'm thinking this would apply before Elder Giant Magic.

If every Tier 1 spellcaster was required to take these flaws/feat, would they still be playable?

Cause, you know, the mundanes actually get a swing at stopping a spell from being cast...

[Unbeliever]

No. Players like to do cool things. Having a player wait around to do things will lead them to avoid it or try to find workarounds.

If moving these classes and builds close together is the goal then there are better ways to do it.

[Amechra]

Well, I was actually asking so that I could figure out some backstory things.

Plus, I think that this kind of build could be fun for a BBEG... especially if they had one of those class features that let you cast spells quickly (like Anima Mage's capstone).

"You have a minute to go in and disrupt the mage while he's casting Apocalypse from the Sky. Don't screw this up."

[Cyclone Joker]

Elder Giant Magic: For each round that I delay (up to 3 rounds), I get a +1 to CL.
Meticulous Magical Methods (Flaw): I'm flat-footed in any round in which I cast a spell, and I can't cast defensively.
Ponderous Spellcaster (Flaw): My casting times are doubled; I'm thinking this would apply before Elder Giant Magic.

If every Tier 1 spellcaster was required to take these flaws/feat, would they still be playable?

Absolutely. It would shift the power a bit away from wizards, and would make scrolls godly. Druids would still be druids, Persistomancy would be better, Contingencies would be more necessary, and blasting would suck even more. It wouldn't change the problems of a prepped caster being untouchable, and being able to end encounters in a single spell, just require more preparation and thought when playing. Oh, and tortoises. It treats a symptom decently, but the real problem is still there.

My only real problem with this, beyond it hurting already weak casters, and its interaction with swift and immediate actions.

[Unbeliever]

For encounter construction have at it. Although you don't need real rules for that. That has ever been the province of the DM.

I was responding to it as a general rule especially for PCs.

[Halinn]

If one were to change casting times as a houserule to nerf casters, I wouldn't go further than making things into a full round action. This would remove the option of moving while casting, while not changing the flow of combat significantly. Having to spend several rounds to cast just means that uberchargers et al. will have finished the combat by the time you're ready to give them Haste.

[Rebel7284]

I have been thinking about a flavorful idea for a caster:

Primeval Giant  Half Giant with the following feats:
Elder Giant Magic
Primitive Spellcaster
Iron Will (Prereq, can be picked up from a location if allowed)
Reserves of Strength(Dragonlance Campaign Setting)

I can totally see:
Enemy#1: Why is that powerfully built barbarian jumping up and down in place screeching at us and waving his hands around?
Enemy#2: I dunno
-- 18 seconds pass
*BOOOOOOOM*
Wizard: Owwww *little stars spinning around his head*

[Amechra]

The most hilarious way to use Primordial Spellcaster is to have some way of casting all your spells Silent, Stilled, and with Eschew Material Components. Shadowcraft Mage works the best for this, since you only have to figure out a way to get it onto Silent Image, and then you can kick all the asses. So you cast all your spells as gibberish rituals!

Not as good as the random suggestion that I saw somewhere of using Nonverbal Spell to cast spells by using orgasm sounds, but almost as good.