D&D 5E Quick Question on AC and Proficiency bonus

[Leatherhead]

Your ac doesn't raise that much because they wanted kobolds to stab you no matter if you are level 1 or level 20. Instead, you get more hp.

What's really odd is that none of your group has an ac of 16 or higher. Did nobody take a class that can use heavy armor or a shield?

 

[The Crimson Binome]

I'm trying out 5E, and it feels that for reasons of symetry, proficiency bonus should be added to Armor Class. I can't find a mention of this in the rules. How is it?

"Symmetry" is not a good reason for a game rule to exist. That being said, it would make a lot more sense if two high-level characters were roughly as accurate against each other as two low-level characters were, and this disparity forms the root of the major inconsistencies within 5E.

From a mechanical perspective, high-level combat would be tedious if you just added +Proficiency to everyone's AC. High-level characters have tons of HP, but their attacks don't deal much more damage than they did at low level. The way it's set up now, high-level characters are much more accurate against each other, because that's the only way to get through those huge piles of HP at a reasonable pace. Low-level characters don't have many HP, so they drop from a couple of attacks, which means they need a (relatively) higher AC in order to not die instantly. As you gain levels, HP takes over the burden of survivability that AC originally held.

The up-shot of all this is that high-level characters are constantly covered with minor nicks and scratches that they have no way of avoiding, while low-level characters are either perfectly fine or they're unconscious and bleeding out. Fixing this issue would require a complete overhaul of the HP and damage calculations, and chances are that they'd break the game along the way.

 

[The Crimson Binome]

5e was designed to avoid the 'treadmill effect'.

That is, if all the numbers raise at the same rate, they're not really raising.

It also means that even at higher levels weaker creatures still remain a threat. So you can have a combat with a couple tough monsters as well as many weaker ones and the weaker ones will make it much more difficult.

Which is really weird logic, if you stop and think about it. The treadmill effect only occurs if you're consistently fighting enemies that are the same level you are, such that both sides receive an equal benefit. Even the suggestion that you might fight a lower-level enemy should render that logic invalid, since the sides would receive unequal benefits.

The only reason to scrap the AC bonus was because, not only did they want you to fight lower-level enemies, but they also wanted them to remain a legitimate threat at higher levels. (Which seems kind of at-odds with the whole concept of having character levels in the first place.)

 

[BlivetWidget]

Which is really weird logic, if you stop and think about it. The treadmill effect only occurs if you're consistently fighting enemies that are the same level you are, such that both sides receive an equal benefit. Even the suggestion that you might fight a lower-level enemy should render that logic invalid, since the sides would receive unequal benefits.

The only reason to scrap the AC bonus was because, not only did they want you to fight lower-level enemies, but they also wanted them to remain a legitimate threat at higher levels. (Which seems kind of at-odds with the whole concept of having character levels in the first place.)

I actually feel like it makes a lot of sense and really is at the core of 5e design. Typically it's referred to as "bounded accuracy" but the name doesn't really matter.

I feel like this quote from Rodney Thompson summarizes it better than I would:

The basic premise behind the bounded accuracy system is simple: we make no assumptions on the DM’s side of the game that the player’s attack and spell accuracy, or their defenses, increase as a result of gaining levels. Instead, we represent the difference in characters of various levels primarily through their hit points, the amount of damage they deal, and the various new abilities they have gained. Characters can fight tougher monsters not because they can finally hit them, but because their damage is sufficient to take a significant chunk out of the monster’s hit points; likewise, the character can now stand up to a few hits from that monster without being killed easily, thanks to the character’s increased hit points. Furthermore, gaining levels grants the characters new capabilities, which go much farther toward making your character feel different than simple numerical increases.

Now, note that I said that we make no assumptions on the DM’s side of the game about increased accuracy and defenses. This does not mean that the players do not gain bonuses to accuracy and defenses. It does mean, however, that we do not need to make sure that characters advance on a set schedule, and we can let each class advance at its own appropriate pace. Thus, wizards don’t have to gain a +10 bonus to weapon attack rolls just for reaching a higher level in order to keep participating; if wizards never gain an accuracy bonus, they can still contribute just fine to the ongoing play experience.

This extends beyond simple attacks and damage. We also make the same assumptions about character ability modifiers and skill bonuses. Thus, our expected DCs do not scale automatically with level, and instead a DC is left to represent the fixed value of the difficulty of some task, not the difficulty of the task relative to level.

 

[The Crimson Binome]

I actually feel like it makes a lot of sense and really is at the core of 5e design. Typically it's referred to as "bounded accuracy" but the name doesn't really matter.

They are distinct-but-related issues. The treadmill effect is the observation that scaling bonuses on both sides is pointless, if both sides are always the same level. Which is true, of course, but only within the context of that absurd premise. It's a criticism of 4E, specifically, because of the way it encouraged DMs to stick within a very narrow band of encounter levels.

Bounded accuracy is the design principle that anyone should be able to attempt anything, without relying on natural-20 rules to guarantee a possibility of success. It's more of a personal preference thing, rather than a mathematical observation. But it's a preference that's getting less and less popular as the years go by, and the flaws in the implementation become less deniable.

There is some interaction between the two issues, but it was never necessary to implement bounded accuracy as a counter to the treadmill effect, since the treadmill effect falls apart under its own weight as soon as you remove it from its original context.

 

[BookBarbarian]

It seems to me that if you add proficiency bonus to Attack and to AC, you might as well just get rid of it.

Edit: from combat anyway

 

[Charlaquin]

They are distinct-but-related issues. The treadmill effect is the observation that scaling bonuses on both sides is pointless, if both sides are always the same level. Which is true, of course, but only within the context of that absurd premise. It's a criticism of 4E, specifically, because of the way it encouraged DMs to stick within a very narrow band of encounter levels.

Bounded accuracy was conceived very specifically as a response to the “treadmill effect.”

Bounded accuracy is the design principle that anyone should be able to attempt anything, without relying on natural-20 rules to guarantee a possibility of success. It's more of a personal preference thing, rather than a mathematical observation.

This is not accurate. Anyone being able to attempt anything (within reason) is a consequence of bounded accuracy, but it is not its guiding principle, nor the reason for its inception.

But it's a preference that's getting less and less popular as the years go by, and the flaws in the implementation become less deniable.

Uhh... Citation needed? Bounded accuracy is a very popular feature of 5e, and one of its key selling points.

There is some interaction between the two issues, but it was never necessary to implement bounded accuracy as a counter to the treadmill effect, since the treadmill effect falls apart under its own weight as soon as you remove it from its original context.

Just because you sometimes pit PCs against threats significantly above or below their level doesn’t mean the treadmill effect isn’t a problem. As a result of the treadmill, threats significantly below the level of the PCs cease to be actual threats past a certain point, because they are incapable of hitting the PCs. Likewise, threats significantly above the PCs level are completely insurmountable because the PCs cannot hit them. Far from solving the problem of the treadmill effect, this is in fact another problem caused by the accuracy treadmill, which Bounded Accuracy also solves.

 

[The Crimson Binome]

Just because you sometimes pit PCs against threats significantly above or below their level doesn’t mean the treadmill effect isn’t a problem.

That's not a treadmill anymore, once both sides are at different points. Just because you sometimes pit PCs against same-level threats does not mean it's worth sacrificing every other fight in the name of slightly simplified math.

As a result of the treadmill, threats significantly below the level of the PCs cease to be actual threats past a certain point, because they are incapable of hitting the PCs. Likewise, threats significantly above the PCs level are completely insurmountable because the PCs cannot hit them. Far from solving the problem of the treadmill effect, this is in fact another problem caused by the accuracy treadmill, which Bounded Accuracy also solves.

Whether or not this is a problem is entirely matter of perspective. Personally, I find it problematic that a couple of town guards with longbows are capable of dropping an adult dragon, and that a master of Arcana could possibly fail at a task which can be completed by a novice. I don't find it remotely problematic when a team of powerful heroes can beat up a bunch of goblins without getting hit.

Auto-scaling level bonuses would allow existing level disparities to be felt more effectively, instead of the current situation, where level is almost irrelevant to most tasks.

 

[Tony Vargas]

I'm trying out 5E, and it feels that for reasons of symetry, proficiency bonus should be added to Armor Class. I can't find a mention of this in the rules. How is it?

It does not, and, yes, it would make sense if it did (and, instead, say, hp inflation was less pronounced).
It's just a design choice, and largely an aesthetic one.

• "Bounded Accuracy" is a feature of 5e, and AC that ascended with level would be contrary to it's small-number aesthetic appeal.
• Classic TSR editions features AC that scaled only with the acquisition of better armor & magic items (and increasing dex), not with level, alone. AC that did scale with level, by itself, would be contrary to that retro aesthetic, which 5e does pursue.

This seems odd, you will hit and be hit more and more as you advance.

Yes.
Any modeling of defensive skill can be assumed to bundle into Hit Points - classes that are better in combat have bigger HD, so more hit points, so they're generally better at defending them selves. Of course, that's bundled in with lots of other factors, like, wolverine-like primal toughness (Barbarians d12 HD), or maybe even magical wards and the like (casters at d6 & d8 instead of d4 like in the olden days). So, even though the classes you might think would be best at parrying attacks & the like, the Fighter (d10 HD) and the Rogue (d8) don't have the highest HD in the game, it's not without reason, and you can imagine their defensive-duelist-style skills as being modeled with hps.

 

[Tony Vargas]

Personally, I find it problematic that a couple of town guards with longbows are capable of dropping an adult dragon

Well, a couple dozen (or hundred) ordinary longbowmen.

and that a master of Arcana could possibly fail at a task which can be completed by a novice.

That's really up to the DM, because he could simply rule that there's no uncertainty involved when the master undertakes the task and simply narrate success, but call for a check (or narrate failure) from the novice.

I don't find it remotely problematic when a team of powerful heroes can beat up a bunch of goblins without getting hit.
Auto-scaling level bonuses would allow existing level disparities to be felt more effectively, instead of the current situation, where level is almost irrelevant to most tasks.

That's true of resolution done with /just/ a d20 (especially contested checks), but, at least in combat, once hp/damage come into it, level disparities are very clearly felt.