D&D 5E Why no Proficiency bonus to AC?

[Sunseeker]

It would certainly add more meaning to being proficient with armor. But it would immediately make all regular armor superior to magical armor, as the best magical armor would only offer a +3 bonus, at level 1 you'd get a +2 bonus to any armor you're proficient in and it would only go up from there. Followup: what happens to classes who have special features instead of armor? Dragon Sorcerer, Monk and Barbarian? A 1st-level Fighter in good armor with a shield and proficiency outpaces a Monk AND a Barbarian with 20's in Dex and Con/Wis. A Dragon Sorcerer caps at 18 so they're majorly left in the dust.

 

[Tony Vargas]

So your ability to hit monsters doesn't change, without magic items; it even falls behind if you pick up feats instead of ability boosts. But the ability for monsters to hit you continues to grow, unless you use magic items to boost your AC.

Now, this might be because there are more ways to boost your AC than there are ways to boost your attack. It's still weird, and I'm not sure that I like it.

It's classic feel all the way, that's exactly what the game's been like for most of its history. You have more hps (tons more in 5e), and, in AD&D you had across-the-board scaling Saving Throws to help you survive being hit more.

I guess a corner case where it kinda breaks down a little is if you have a hypothetical series of monsters over a range of levels that forced a save on a hit, and were hammering your 'bad' (non-proficient, tertiary-stat) save. They'd not only hit you more often for more damage, but the save would get harder and harder for you to make - you'd be getting 'worse' as you leveled.

In order to put in scaling player AC, though, we'd either need to base AC at 8 + modifiers, like save DCs, or we'd need to bring back weapon proficiency bonuses, which would seem odd in the system when they already have proficiency bonuses.

Adding in proficiency to AC would require a lot of changes.

Or just not have it stack with armor. The 5e general rule is already that different AC formulas don't stack. So you have 'active defense' or 'parry' or whatever:

8 + Proficiency Bonus + DEX

All other AC formulas stay the same. It acts as a 'floor' for armored characters who lose their armor or are forced to use sub-standard-for-their-level armor.

If you want to make it interesting, let any stat stand in (perhaps only under a given condition) for DEX.

For instance a wizard could have a defensive proficiency:

Magic Wards: AC = 8 + Prof + INT when conscious, able to speak, has a hand free, and is not Concentrating.

Melee types might have 'parrying:' AC = 8 + Prof + STR (if using a regular weapon), DEX if using a light weapon, or CON if using a Shield.

Etc...

 

[ProphetSword]

Armor class doesn't need to improve as you go up in level; because, hit points cover that. An adventurer with more hit points isn't getting stabbed more times than a low level character, he is avoiding more blows by dodging and rolling with the damage and turning lethal blows into mere scratches. What would kill a neophyte adventurer is knocked away by a seasoned warrior, who shrugs away the pain and keeps on swinging. Hit points are more than just health, they are an abstract representation of many things (fatigue, dodging, etc). It has always been this way.

The other reason why AC shouldn't scale with level is that rolling dice and constantly missing is boring. You and the enemies hit more often in 5e, creating for a more dynamic combat. Constantly swinging at air in previous editions was frustrating. Miss, miss, miss, miss again...

 

[Sunseeker]

The other reason why AC shouldn't scale with level is that rolling dice and constantly missing is boring. You and the enemies hit more often in 5e, creating for a more dynamic combat. Constantly swinging at air in previous editions was frustrating. Miss, miss, miss, miss again...

Hitting and having to chew through a million HP really isn't any different statistically. Hitting 5/20 times with a goal of dealing 50 damage or hitting 15/20 times with a goal of dealing 150 damage is the same. Whichever you find boring is a matter of taste. I'll posit though: there was greater objection to 4E's "bucket o'hit-points" model than there was to 3E and prior's "can't touch this" model.

 

[77IM]

Attack bonus increases directly with level, but damage doesn't. Damage scaling comes from other means, like extra attacks or sneak attack or smite or rage or ... whatever it is that rangers get. Instead of AC scaling, hit points scale.

There's a nice symmetry to having AC scale the same way Attack does. But to maintain the overall ratio, you'd need for damage to scale a lot more, or hit points to scale a lot less. It would certainly be doable (and I'm kind of annoyed that 5e didn't do it this way) but it would be a somewhat extensive change to the system.

 

[TheLoneRanger1979]

The idea behind the current system is that 100 orcs (insert other horde of low CR creatures) is scary to a 20th level character. If you take away bounded accuracy you can't use these creatures in higher level modules, as they won't hit short of a crit.

This. Always this.

I'll posit though: there was greater objection to 4E's "bucket o'hit-points" model than there was to 3E and prior's "can't touch this" model.

The Oblivion style scaling (power creep) was also a thing. At least for me and my group.

 

[Horwath]

Hitting and having to chew through a million HP really isn't any different statistically. Hitting 5/20 times with a goal of dealing 50 damage or hitting 15/20 times with a goal of dealing 150 damage is the same. Whichever you find boring is a matter of taste. I'll posit though: there was greater objection to 4E's "bucket o'hit-points" model than there was to 3E and prior's "can't touch this" model.

I personally find bucket'o'HP better and even more fun than must roll 19+ on d20 to do anything.

And 4E was easy to trim down the bucket.

just cut all HPs(both PC's and NPC's in half).

...
and remove +1/2 bonus per level to everything and you even have a decent edition

 

[ProphetSword]

Hitting and having to chew through a million HP really isn't any different statistically. Hitting 5/20 times with a goal of dealing 50 damage or hitting 15/20 times with a goal of dealing 150 damage is the same. Whichever you find boring is a matter of taste. I'll posit though: there was greater objection to 4E's "bucket o'hit-points" model than there was to 3E and prior's "can't touch this" model.

I was talking about fun factor. Players who hit more often have more fun and can put their powers and special toys to use more frequently. Since D&D is a game and not a scientific simulation, I am more concerned with players having fun, even if the outcome is the same.

 

[ChrisCarlson]

I'll posit though: there was greater objection to 4E's "bucket o'hit-points" model than there was to 3E and prior's "can't touch this" model.

Interesting. What has lead you to believe this? And do you have anything that points to such a theory? It just seems counter to what I would have guessed, is all. Give than 5e was designed through an extensive, open public survey and playtest...

 

[Sunseeker]

Interesting. What has lead you to believe this? And do you have anything that points to such a theory? It just seems counter to what I would have guessed, is all. Give than 5e was designed through an extensive, open public survey and playtest...

Mostly memories of discussion back when 4E was around.

I was talking about fun factor. Players who hit more often have more fun and can put their powers and special toys to use more frequently. Since D&D is a game and not a scientific simulation, I am more concerned with players having fun, even if the outcome is the same.

Which, as I said, is relative. If YOUR players have more fun that way, sure cool. But there's more than one way to have fun. I personally don't have fun doing that.