I've compiled a list of problems with GWF and damage-on-a-miss over at Wotc forums:
Hello forum, I've compiled a list here of problems with Great Weapon Fighting style, which I will now quote:
Great Weapon Fighting
When you miss a target with a melee weapon
that you are wielding with two hands, the target
still takes damage from the weapon. The damage
equals your Strength modifier. The weapon must
have the two-‐handed or versatile property to
gain this benefit
Problems that I see with this mechanic (being a game creator with over a dozen high profile, AAA titles to my credit):
1) It allows 1st level fighters to do damage every round they attack. If you cannot see why that violates how D&D combat is supposed to work, I don't know what to say. It's not how D&D fighting has worked in any game I've ever played.
2) No human is so perfect that he can never fail to harm his opponent any time he attacks them. Certainly not a 1st level Fighter fresh out of boot camp
3) Armies of Ogres or Trolls using PC creation rules can use this to auto-win any battle due to their excessive strength and HP in the first round or two of battle, by concentrating firepower on one target near them.
4) If used against PCs, they will not appreciate the DM being able to kill them without any input or agency from either D20s or damage dice
5) It ignores which weapon you're using, so a longsword used two-handed has the same effect as a greatsword or greataxe. Removing the importance of weapon selection is something feedback rejected
6) The higher level you get, and thus better accuracy, the less often the fighter will benefit from his fighting style. Fail. Simple fail.
7) All objects being attacked, no matter how small, will be auto-smash. Has important ramifications for epic battle scenes where crystal balls need smashing on time. Or ropes need cutting to lower the drawbridge. It removes the agency of the dice from the game, which, being a game where dice are used when outcomes should be uncertain, is bad form.
8) It turns all enemies with HP < # of attacks per round * str mod into insta-kill minions, up to 20 HP. That was previously a level 20 fighter ability in a previous packet. Should give a clue. This is terrible news for wizards, both PC and NPC wizards, who will be insta-gibbed.
9) It completely negates all defensive fighting styles : AC +1 ? Useless. Granting disadvantage? Useless. Investing into 30 AC, with artifacts, spells, buffs, invisibility, disadvantage? Useless
Actually, it basically means a fighter in full plate and magic is no better defended from incoming damage occurring than a naked, prone, disarmed and helpless princess on the floor.
10) If you have less than X (mentioned above) HP vs a foe with this ability, your armor is useless, as you will die no matter what, anyway. Ever single time.
11) There is no point in rolling to-hit or damage when a fighter attacks a foe he knows has less than his GWF damage. This can be 20, or it could be 50, 60 per round. Insta-kill terminators, here we come!
12) There is nothing specifically relating to the use of two-handed weapons even hinted at in the style. It could easily apply to any other weapon type, TWF, S&B, bare-hands.
13) It says you miss with your weapon, but your weapon does damage. Not you doing damage, your weapon doing the damage. Since the weapon missed, how is this possible? Doesn't bother explaining (it can't, because it's nonsense)
14) It makes a mockery of the english language, basic logic, and basic physics, and forces you to interpret HP as being essentially a meaningless stat. Contradictory definitions = meaningless.
15) Wizards have unerring striking in a daily spell, Magic Missile, not a cantrip. This is essentially an at-will Magic Missile for fighters, mechanically. Actually better since it can potentially do much more damage. So it fails on a balance level against an iconic wizard spell, which currently costs them a daily slot to use.
16) Wizard cantrips do not do damage on a failed saving throw, and thus never miss. Why should fighters get that? They already get multiple attacks per round to scale their damage
17) Spells with saving throws that are succeeded by the target are still within the area of effect of the spell. The analogy is that they hit, but roll less damage. This mechanic is like a spell with NO saving throw for zero damage, no matter defensive abilities like Evasion.
18) In the last round of battle, every monster from the lowest kobold, to the greatest dragon, stands a good chance of being auto-killed without any dice rolls, precisely in the most dramatic possible moment of their existence. Removing dramatic tension in epic death scenes, and nail-biting will he / won't he be killed this round, is one of the cornerstones of D&D fun. Finishing off that dragon with a lame auto-damage mechanic is probably the thing that bothers me the most about this. In the last round of battle, at low HP, a dragon is no tougher to kill than a naked, blind, and gagged kobold.
Any additional flaws? I intend to write this as an open letter and hound the designers until they respond to each bullet point one by one.
If you discover valid reasons why any item here does not belong on this list, please discuss below.
