Lizard said:
I thought we already had these discussions now.
"Ranger overpowered, see my unlimited attacks per round exploit"
"Clerics underpowered, not enough interesting feats!"
I think the strength of 4E is that there are clear "benchmarks" for how powerful something can be. The monster stat guidelines basically tell you the to-hit bonus, defenses, hit points and damage expected for each level.
It shouldn't be that hard to relate that back to the existing PCs, and create guidelines for the powers.
Another strength is that there is decidedly not a power discrepancy between "martial" characters and spellcasters. 3E was inherently imbalanced to the benefit of spellcasters. You don't need any splat books for it. Knock, Scry, Teleport, Disintegrate, Finger of Death, all these spells are in PHB and only accessible to spellcasters.
3E also contained rules element to promote "system mastery". Alertness & Toughness compared to Power Attack or Empower Spell. 4E no longer has this. System Mastery naturally benefits Power-Gamers, since he will analyze these options and find the good ones, while a more "casual" player will just pick what fits his character - and Alertness sounds nice if you're idea of a Guardian-like character, and Toughness sounds good for a Dwarven Fighter...
The question is:
- Does WotC R&D have these numbers stored? (likely)
- Will they continue to use them, even if the team changes, and the pressure to create new books appealing to the gamers (including the power-gamers) increases?
- How well do these numbers support predicting power interaction? The Armor Splinter/Cascade of Steel example indicates that there are instances where it didn't go right, despite all play-testing and number-crunching. Or are these instances all "paper-tigers". Yes, you could create it on paper, but there are disadvantages and they'll not be used in actual play?
My current prediction is:
- Initial Balance is good (except for outliers that a group can simply choose to avoid. There is a difference between cheese and power-gaming.

)
- Party Tactics Optimization will be the best way to power-game, which usually means everyone is involved or no-one is.
- Later books will have to be handled with care, though most feats, powers, and classes will be fine.