To those who believe that humans are incapable of coordinating two hands' actions independently in complex feats of manual dexterity need to get out more. Or even look at youtube a bit.
try "Bach", for starters. Or martial arts. Or dual-wielding forms. Or boxing. Or whatever...the examples are limitless. Whether the human mind achieves multi-tasking with time-slicing focus or true independence is as irrelevant to its perceived effect as a single core system running a pre-emptively multitasking operating system and opening up 8 apps at once is only actually processing one thing at a time.
My point is...humans can do plenty in parallel. I don't want my heroes in D&D to be strictly worse than I am at basic dexterity.
I profoundly disagree that TWF should ever be modelled a single attack with some kind of "baked-in" bonus of whatever. It's pointless to even debate that, because they will not model it that way. It is terrible the way they did it in this packet, but that's something they'll need to rectify.
I, for one, after playing D&D for twenty years, cannot go back to a system with combat rules that are worse than...well, virtually all the editions I've played so far.
I think that more than one action per turn for higher level beings is in keeping with the movies. Conan often slays 2 or 3 before someone takes a swing at him.
A single attack with a single weapon is not a single swing, hit or miss, it's a series of attacks, parries, dodges, and we choose to represent that with a simple, single attack roll.
That is only one interpretation of what an attack roll means.
I - and possibly the poster you were replying to - am in the camp that one attack roll is equal to one swing of the sword. Whether or not that is realistic, I'm not entirely sure, not being a person who uses a sword on a regular basis. But that's my interpretation, that's how I present it in game, that's how I visualize the mechanics working.
With that understanding, TWF should provide for two attack rolls, one with each weapon.
Obviously these two worldviews are at odds with each other and are impossible to reconcile in the same system, so 5e is either going to have to come out and say what an attack roll (and similar) represents (thereby either making you or me unhappy), or provide options for both interpretations (TWF usable as a single-attack thing with bonuses, or two separate attacks).
I think this might actually be an AD&D vs 3/4 thing. In 3 and 4, a round is 6 seconds, and the text says something like "an attack roll represents your attempt to strike your target".That is only one interpretation of what an attack roll means.
I - and possibly the poster you were replying to - am in the camp that one attack roll is equal to one swing of the sword.
It is important to remember that in AD&D a round lasted about 1 minute, not 6 seconds. That's a very big difference.When making an attack, a character is likely to close with his opponent, circle for an opening, feint here, jab there, block a thrust, leap back, and perhaps finally make a telling blow.
Since a round is roughly a minute long, it should be easy for a character to move just about anywhere he wants during the course of the round. After all, Olympic-class sprinters can cover vast amounts of ground in a minute.
However, a character in an AD&D game is not an Olympic sprinter running in a straight light. He is trying to maneuver through a battle without getting killed. He is keeping his eyes open for trouble, avoiding surprise, watching his back, watching the backs of his partners, and looking for a good opening, while simultaneously planning his next move, sometimes through a haze of pain. He may be carrying a load of equipment that slows him down significantly. Because of all these things, the distance a character can move is significantly less than players generally think.
I agree, you can interpret it the other way, one attack roll is one swing. I guess combatants are just really, really slow, only doing that every six seconds.
I don't mind if TWF offers two attacks, I just think it's very tricky to balance it at that point - the fundamentals of your damage output change completely, since you only need one hit to get additional damage like Deadly Strike. The response to that is to downgrade your single hit damage, but then if you don't have bonus damage coming from somewhere you're rather behind the curve. It's very difficult to make it an equal option.
I like a 10 second combat round, it's easy to grasp.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.