You're a druid in bird form. You have only a handful of HP. You wanna fly by the guard into the castle. He takes a swing at you as you dive bomb...and guess what? He NEVER lets you through. You always turn into a human since his OA never fails to deal 5 HP of damage.
Why is the guard taking an OA against a bird? (Also - why is the guard statted up as a PC? But that is a seconday question for this particular scenario.)
Let's look at "Damage on a miss" from 4th edition.
You could damage creatures on a miss but for some reason you couldn't kill Minions with it. Why?
Because minions are one-hit kills, the mechanical balance of which is based on a 40% survival chance per attack faced.
Assuming that the D&Dnext designers are doing their jobs well, their mechanical design of kobolds, goblins etc factors in the posibility that, if attacked by a great weapon fighter, they have a 0% chance of survival.
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
Isn't this part of the retro feel of D&Dnext? It takes me back to the days of classic D&D dragon breath ("Save for half of 88 hp of damage? Only max 33 hp? Sorry, I guess you're dead then without any input from either d20s or damage dice!").
Falling damage is another common example of this. 1st level thief with 2 hp who falls 30' down a pit? Oops - no dice roll required!
Ahh, dude, you realize that the wizard still rolls dice for fireball damage, then it's halved on a successful save, right?
The agency of the dice is still there.
If the opponents have 3 hp (like goblins) then the dice roll (6d6 in the current playtest) is irrelvant.
I don't want any monster to be killed by auto-damage, it's lame
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Dice rolls should matter. Dice rolls should dictate when you die, or when you kill.
So am I to gather you are also campaigning for the removal of magic missile and AoE spells in their current forms?
I don't think it's a 1st level character power.
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If damage on a miss is included, I'd prefer it to be a specialized ability at higher level.
Great weapon fighter is a specialised ability. And what difference does level make? The OP concedes the ability is balanced.
I also don't think a flat "if you miss you still deal damage" works, as it allows for damage on natural 1s and the like.
And?
A fireball can do damage even on natural 1s on the damage dice, and agaist natural 20s on the saving throw.
These are choices about how to allocate prospects of success, that's all. In the case of the great weapon fighter they have gone for increased DPR in the form of steady output rather than spike damage. It gives the great weapon fighter a "dreadnought" vibe, quite different from (for instance) the rogue's sneak attack.
The definition of HP is irrelevant to the phrase "When I miss you with my sword my sword damages you"
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You can't kill or even hurt or damage a foe with your weapon, unless that weapon is making contact. If it isn't, then it's just tiring them, and you can't easily kill someone by tiring them, especially not if they would otherwise have no trouble running all day long.
So you would be OK with the ability if it was rewritten "When you miss a target with a melee weapon that you are wielding with two hands, the target still takes damage"?
In any event, a "miss" in D&D has never been equivalent to a miss in natural language, as has been clear at least since Gygax's DMG. "Misses" include attacks that are blocked, parried, etc.
Furthermore, there is the broader point that this is a player fiat ability. It is an ability that ensures that every attack is, in some limited sense at least, a hit. The character has only partial success (STR damage) or full success (W + STR damage). The reason that it is described as "damage on a miss" rather than "your misses become partial hits" is because there currently is no defined mechanical state of "partial hit", and there is no need to define such a state for this ability to be set out.
What is the criteria you feel is required to keep a controversial mechanic in the core rules instead of an optional tactical module?
It's not up to me. It's up to WotC, and I assume that their criteria will be commercial ones.
They will therefore recognise that some of their current customer base (eg those paying for 4e DDI subscriptions) probalby want abilities like the one under discussion in their game. And that by removing them they risk losing those customers. They will likewise recognise that some of their desired customer base (eg a certain style of 3E/PF player) do not want abilities like the one under discussion in their game. Assuming they have reliable market research, they will be able to crunch the numbers. Assuming they have imaginative desingers, they may also try and come up with options that satisfy both groups. An example of that might be their current variant on Vancian casting.
For instance, let's assume that the hit rate is 60% (as in 4e). And lets assume a 5 round combat is the norm. (Both these assumptions are stipulated by me based on general familiarity with D&D, not on detailed mathematical analysis of the playtest.) The current great weapon fighter therefore, in a round, does 3W+3STR by hitting, and 2STR on misses.
Let's say STR = 4. And W = 7.
Then you would get close to the current expected damage by saying that, once between short rests, the great weapon fighter can declare a miss is a hit. (Not unlike Ace in the Hole.)
Obviously more maths would have to be done. And I haven't even tried to consider whether this will break down at higher levels.
Of course, at this point you no longer have anything that seems very distinctive to the great weapon fighter, but then that is equally true of the existing Archery ability, which is simply +1 to hit.
Whatever path they take, however, I think they are going to include
something that makes core fighter's attractive to existing 4e players. It's not coincidence or error that exlains why reaping appeared in earlier drafts, and why the ability has now reappeared.