I would rather success come from from what we, the players, decide to do and how we go about it than from whatever build options we choose. If the system doesn't support good play being the largest determining factor in success then it can shove off.
How do we assess this? Can a 1st level character succeed over a 21st level character? If not, does that mean that good play is not the largest determining factor in success? If we are all 1st level, so we remove that aspect, and we roll dice for our attributes, who will be more successful, the fellow with below average, average or above average rolls? Is judicious resource selection not part of good play? Is "picking the right spells to memorize and the right time to cast them" good play, but "adding the right spells to my spell book" not good play?
I would also suggest that the greater the variance in effectiveness of choices the player must make for their character, the more build, and not play, determines success. Moving the game more to "play decisions" and less to "build decisions" requires reducing the choices and/or equalizing the choices. If every character has the same stats, then decisions in play become much more significant as the determinant of success, don't they?
The player should be the one to make the decision on how to allocate character resources for each pillar at creation and level up. If the player wants to create a 'do nothing but combat' Fighter they should have the options to do so. If they want to create a 'good at combat, but swashbuckling charismatic sailor' they should be able to do that too, via choices at character creation and level up.
The default should be close to even in all three pillars, then players can choose to deviate from there. Templates could even be created that allow them to quickly pick a character type that adheres to one or two pillars and ignores the remaining pillars. However at all times it should be the players choice and not the games choice. You should never hear "Well, I want to play a Fighter so I guess I'm only good in combat and can't do anything in the social or exploration pillars." That should just not happen, instead we should hear: "Well, I want to play a Fighter so I guess I need to pick these options to be good at the <combat/social/exploration> pillar."
I think there should be defaults to and I also think the defaults shouldn't stray too far from the 33% in each pillar paradigm. Where I disagree is that players should be able to go 0% in one pillar in order to go 66% in another. It should be up to them.
I think another issue to consider here is the target audience. An experienced player can likely look at the default, look at his options, and decide "I am OK sucking on ice at social interaction to be a Combat Wombat. I will sell out social skills for combat ability." A rookie player seems much more likely to focus in on one area and short change another if the rules do not give very clear guidance. I don't think you or I are the target market. We're gaming already. But for D&D (and gaming in general) to survive and thrive, it needs to attract new gamers, who build their first character and have a blast playing the game. If they get sucked in to building a character who excels in one area (and overcomes challenges in that area with ease) and sucks in other areas (so experiences some combination of boredom and frustration facing those challenges), he's probably back to spending his recreational time and discretionary dollars on some other hobby or pastime. Me and me 20+ year gaming group probably don't care - until the market shrivels up enough that we're not getting anything new published, anyway. But the business - the publishers - they need to care about those first-time gamers.
I'd rather it not be silo'd off into an optional module. I have a feeling those are going to not be very well tested or make very large changes to the game. It should be designed into the default game so that it can be fully tested before release.
I thought we already established your preferred default was close to even across all three pillars. That said, of course, the game could certainly provide the defaults and options for deviating from them in the core rules. However, I think it is important to clearly communicate the risks and possible impacts on your character, and on the game, of deviating from the defaults. Now, maybe that means the core rules suggest about equal resources, allow for tradeoffs to each pillar being between 25% and 50%, and provide modularization for going beyond that, or maybe they provide a default of "equal", optional rules for tradeoffs and clear cautions about where the design of the game assumes those tradeoffs will cap out, and what going beyond those assumptions is likely to cause. But I don't think they can playtest "everyone is even in all pillars" and "some guys are 100%/0/0" effectively, or design a game that works equally well around either of the two as a standard/default. Do you consider that viable?
Because PC design is, mechanically, all about the allocation of scarce resources, and weapon choices & the like are resources in D&D. And not all choices are equal.
So why include lots of different weapon choices if we know from the start only a few will really be viable? Some, of course, are viable only with resources invested, so that creates a tradeoff (do I take Exotic Weapon Proficiency, or enhance my skill with a martial weapon? do I use a one handed weapon or forego the shield for more damage?). But if we have a martial weapon that does higher damage at greater reach with the same critical as a longsword, say, why should anyone use a longsword?
Most of the weapons were real world, but few were used at the same time in the real world. When the Romans developed metalworking to be able to make short swords, they ruled the world. Who would use a short sword in King Arthur's time? Or in Renaissance Italy? Who uses bows today? Not anyone who can access a gun! If some weapons are clearly superior, then the others should logically be doomed to obscurity. Especially in a game where the time required to train with a more sophisticated weapon isn't really factored in.
There are plenty of fighter feats out there. At low levels, a power attack and monkey grip are mechanically similar.** As you level up, though, power attack is obviously mechanically superior. But only monkey grip lets you use an oversized weapon. For some, that tradeoff is worth it, for some it isn't.
Power Attack in 3.5 or the significantly modified Power Attack in Pathfinder? To me, if one feat is so clearly superior that, from that myriad of possible choices, over half the fighters pick this one, then it's pretty overpowered.
But I tell you what- they're cool to play! The look on everyone's face when your 1st level PHB sorcerer in scale mail with a maul advances to one end of a skirmish line...and breathes lightning at the foes, killing most of them?
If he's one shotting the encounter, leaving the rest of the PC's to clean up after him, I find it difficult to see how he is underpowered.
