16 vs 20 is just as bad as 14 vs 18. Some people think anything less than 20 is subpar. I think 20 is too much to spend for most concepts.
While the difference between 16/20 is the same as 14/18, the difference is that someone with 20 in an attack stat is going to have significant flaws, and someone with a 14 in their attack stat isn't even trying to be significant. With a 16, a player can take steps to increase their accuracy, like taking a weapon with bonus to proficiency.
The problem comes when you have someone with a 16 that
also has a class and weapon choice that do nothing to improve the situation compared to someone that has not only went with a 20, but taken every other option to maximize their attack bonuses, including taking fighter (or rogue), and wielding a +3 prof item (or dagger in the rogue's case).
However, without taking a 16 vs. 20 and adding elements onto it to make the gap wider, the difference is +2. Combat advantage, cover, marking, etc ... +2 is a swing number that is acceptable in game.
You're not understanding what relative means. How is 40% hit rate failing, but 50% hit rate pulling your weight, if default sort of optimal character is 50 or 60%?
If the default for an optimal character is 50% than 50% is going to be pulling your weight.
I understand what relative means. I was pointing out that while there is the same gap between say a character with 25 and 50% hit chances vs. 50 and 75% hit chances, in the latter case both players will be contributing in combat, while in the first case, the person with only 1/4 hit chance is going to be a liability.
Being better than average at hitting isn't anywhere as disruptive as a character that doesn't hit often enough.
Your argument is flawed. You basically state that it is OK to have major discrepancies in power among the players, as long as the DM compensates by giving better gear to the crappier designed characters. How is that fair to the player of the better character? Acquisition of treasure is a longstanding goal of DnD adventurers.
Not necessarily. The "bad" PC is the first person to get a level 6 item. However, the "good" PC will be the first one getting items like the level 10 item, the "best" of the +2 items. Each player trades off being the "best" item. The "bad" player is rewarded with items that directly improve his characters ability relative to the party, while the well built character gets the high level item that applies the same bonus, but has better secondary characteristics. Not to mention this is ONLY the weapon being talked about. It's possible the optimized attacker is in more need of having his defenses boosted ASAP.
Treasure packages are designed so that a party of 5 will get 4 magic items, plus enough gold to buy another one at each level. A "fair" group will rotate who gets the best item at each level. In this system, the optimized player would be getting the best weapon at level 1 (thus a level 5, top of the line +1 item), and the unoptimized player would get the best weapon at level 2 (thus a level 6, bottom of the line +2 item), and so forth.
A DM should design encounters to be challenging to the whole party, and if there is a situation where a challenge to the whole party is actually easy for one character's part but annoyingly difficult for another, then there is something wrong with the game.
First of all, they apparently aren't playing 4e anymore as the challenge isn't just whether or not you hit the monsters. There are monsters that have Reflexes or Fortitude as good as, if not better than, their AC. So, even though by the "math" the wizard and fighter are equally optimized, suddenly the fighter is doing better. Then there are Soldiers, where suddenly people targeting the NADs are doing better.
For leaders and defenders, there are secondary goals that aren't entirely focused on hitting attacks. Even for a rogue who has ridiculous accuracy, hitting on high numbers (targetting NAD with a dagger and combat advantage, etc, etc, etc) still has to get combat advantage in the first place.
I'm not saying that this means it's less important if you hit or not, but that there are ways of challenging the group other than "make sure the best person in the party has a tough time hitting them, regardless of what the rest of the party looks like".
Also, a monster that has defences which "challenge" the uber-optimized player may not have attacks that are challenging to the party ... in fact that character may be hitting the party very frequently. On the other hand, a monster that isn't too hard to hit for the non-optimized character may be able to hit the PCs rarely. There is more that goes into an encounter than just "how often do the PCs hit?". And one PC hitting often does not necessarily make the encounter easy for them ... if they get beat up by the monsters, there is only so much that hitting back will help them.
The point is that this feat does not improve the game. If it was meant to fix the discrepancy between player attack bonuses and monster defenses as you level up, then the implementation is flawed. A better method would be to errata the level up chart in the PhB.
Errata the level up chart to have an arbitrary bonus that is different than anything else they have. Magic items are part of the math as well, and while they do have a level associated with them, the timing of when you get the magic items doesn't have them magically show up at exact points in time. Attaching it to a feat gives players the option of when they wish to get it. Do they want it before level 5 or after. And of course, do they want to take both weapon and implement expertise, or focus their powers on weapons exclusively and take the hit on any implement power they do use, etc. There are options associated with the feat. While it's unlikely anyone would not have it by 15th level, there are still a lot of levels before that where it may or may not be taken.
One of the problems is the person it will benefit least is also the person most likely to take it, and vice versa. Someone that is already squeezing every bonus to attack rolls as he can find is more likely to take it than someone that didn't concern themselves with maximum optimization, when the lower your initial accuracy is, the more helpful the feat is. Still, the person with the unoptimized character benefits from the feat more than the optimizer does
unless the DM decides that the feat is pure powercreep and decides that instead of banning it, he'll up the monsters by an appropriate ammount, which forces everyone to take the feat in order to keep things "as they were".
It was obviously not meant to bring poorly designed characters up to par with the better ones, as feats aren't really that scarce and the better designed characters can take these feats too.
Feats aren't really that scarce, but they are scarce enough for people to complain about feat taxes.
And, while better designed characters can take these feats just like anyone else can, the difference between 50 and 55% is bigger than the difference between 60 and 65%. This feat does nothing to the defences of the PCs. So, monsters that are balanced against the party's defenses are easier to hit by everyone, and a character that is well balanced defensively is able to improve it's suboptimal attack abilities so that it's able to hit often enough to contribute in combat. It
also means that someone that has optimized their ability to hit in combat is even better at it.
EDIT: Since the DM is balancing encounters based on how well the party does, it would be in the optimizers best interest to let the rest of the party "catch up". By making himself better, he has a marginal bonus (if any) as the encounters become harder, and ends up making it harder for the rest of the party that he is relying on. If anything he'd "slow down" so they "catch up" a bit and reduce the relativity so he's not the one doing all the work. Also if the entire party decided not to take the feat than the DM would be changing the encounters accordingly ... so based on the whole relativity thing ... the feat is only mandatory if everyone else is taking it and upping the ante of the encounters as a result.