Simplifying 5e AC
There is a weird gap between armor proficiency and everything else. Armor proficiency just means you get to use the armor without getting disadvantaged on whatever saving throws. Everywhere else, it means you add your proficiency bonus. Let's first imagine a world where dexterity did not improve your armor class: what if your proficiency bonus did, instead? We can use a formula similar to the spell save DC, which is pretty common in other contexts:
AC = 8 + Armor + Proficiency
The trick is that, at early levels, 8 plus your proficiency is really 10. This means that this is a tricky way of saying your spell save DC is 10 plus whatever modifier, but you also get additional modifiers from advancing your character. This same thing applies to our hypothetical AC formula: if you wear a type of armor with which you have proficiency, your base is technically 10 but increases as you advance.
This means a wizard's AC, having proficiency with no armor type, increases from 10 to 14 as they advance. Meanwhile, a fighter could have somewhere from 10 to 16 AC at early levels, or from 14 to 20 AC at later levels—assuming that we have three basic armor types of {+2, +4, +6} and shields don't matter.
This could be useful? Idk
The problem is that there's pretty much never a reason to have your character wear armour they aren't proficient with because of the disadvantage and not casting spells, you'd have to rework all the armour numbers, and it would interact weird with heavy armour which is designed to just give you a flat AC number (same as Tortle's natural armour, etc) plus potentially a shield.
ReplyDeleteI can't find it yet, but the only AC alternative I've ever really liked was the one where instead of enemies rolling to hit PCs, the PCs roll to dodge enemy attacks, and you change their flat AC to a +bonus. If you've got players that really like rolling, it's a nice alternative that can make them feel more active in combat. If you were doing that, adding proficiency bonus to the roll would potentially not be too game breaking.
I really like this idea, but it does result in substantially higher ACs all around at high level. The easiest solution is to reduce HP accordingly, though you're still deviating from the 5e design assumption that 65% of attacks will hit.
ReplyDeleteI too don't love that armor (like language) is a proficiency with which the character never has to make a "proficiency check" of sorts. It seems to me that every proficiency should use the proficiency bonus in some way. I've toyed with the idea of every attack being an attack roll contested by an armor roll, but I know some people are averse to making multiple rolls for every attack like that.
ReplyDeleteBesides, the math doesn't really work for me. A high level fighter with plate armor (+8), a shield (+2), and a proficiency bonus of +6 is rolling +16 for armor, but only attacks at +11 (assuming +5 Strength).
Maybe get rid of the flat AC values entirely, and instead do something like this?:
-Unarmored AC is just the Dexterity modifier (unless the character is a barbarian or monk or whatever)
-Light armor uses PB + Dexterity modifier: +5 at 1st-level for Dex-specialized characters (equivalent to a goblin's attack, for example)
-Medium armor can use PB + the better of the character's Strength and Dexterity modifiers (character's choice) +1 (to make it better than light armor): +6 at 1st-level for Str- or Dex-specialized characters
-Heavy armor uses PB + Strength modifier +2 (to make it better than light and medium): +7 at 1st-level for Str-specialized characters
That's assuming there's just three types of armor. If you wanted to go more granular (i.e. leather and studded leather, scale mail, half plate, etc.), each time a character gets the next best armor of their type (i.e., they upgrade from leather to studded, or from splint to plate), they get another +1.
I've thought about it. Not sure I really want to fiddle with it much.