View Full Version : A few notions on AC, mitigation differentiation, and under-represented options.

12-30-2011, 08:32 PM
This is based on a few premises, which I'll elaborate on as we get to each point, but the basic philosophy is this: Pursuing defense should matter, and using your head should as well.

1) Attack progression, swing speed of mobs, raycasts, and networking transmission.

One of the missing components mob side from core, is that monsters with class levels gained the same variance in to-hit as players.


Base Attack Bonus

A base attack bonus is an attack roll bonus derived from character class and level or creature type and Hit Dice (or combinations thereof). Base attack bonuses increase at different rates for different character classes and creature types. A second attack is gained when a base attack bonus reaches +6, a third with a base attack bonus of +11 or higher, and a fourth with a base attack bonus of +16 or higher. Base attack bonuses gained from different sources, such as when a character is a multiclass character, stack.

Now for DDO, we're looking at a 20/20/25/30/30 listing using the chargen as a quick look-up, which in and of it's-self if given to mobs would provide a 10 point swing over the course of a round if simply translated literally.

In addition, it's a pretty straightforward assessment to make that when 12 twf players were swinging at-speed the network and servers got more than a bit choked on down, and you not only had to reduce the ray-casts taking place, but also up the network pipeline, so simply making mobs hit more often isn't really advisable.

That being the case, the system you've used at present to account for the variance in attack rates has been to up the base incoming damage to account for it. Not necessarily the worst notion in the world, however, mitigation methods haven't kept up in terms of keeping the variance in attainable gear progression anywhere close to other progressions such as simply beating it on down before it gets any more swings in.

A variation on this theme would be for a mobs visual cue to represent several swings that round, using either a progressive or regressive to-hit system for additional damage multiplication, though to enhance the meaningful range of swings, as well as stick to the main point of d20, namely being able to do most of the math in your head, or at least the back of a napkin, I would advocate for 5 point or even 10 point steps as follows:

Damage = ((mobToHitRoll-playerAC)/5)*(WeaponDamage+STR) caped at 5 for a 25+d20 variance (so a 45 point swing in effective AC), with every 5 points of ac above the dice threshhold-25 shaving off 1 W+STR,


Damage = ((mobToHitRoll-playerAC)/10)*(WeaponDamage+STR) caped at 5 for a 50+d20 variance (so a 70 point swing in effective AC), with every 10 points of ac above the dice threshhold-50 shaving off 1 W+STR

Side effects of interpreting mob swings as full round actions also include dr as multiplicative, so:

Damage = ((mobToHitRoll-playerAC)/5)*((WeaponDamage+STR)-DR) which would be a relative boost to dex, S&B, and DR builds, though each in different ways, since dex/wis would shave off a step, dr would shave off portions per step, and shields would continue to shed a blanket percentile after the fact (or before. ends up the same number either way there)

2) Flanking, pathing, attacks of opportunity, and quest geometry.

The first part of the suggestion dealt purely with raw numbers, and takes no account of the quest layout or mob count it'sself, as does the lions share of the game at this point.


When making a melee attack, you get a +2 flanking bonus if your opponent is threatened by a character or creature friendly to you on the opponent’s opposite border or opposite corner.

The mob AI spends quite a lot of time and server rescources attempting to outmaneuver players for a benefit, that, frankly, is laughable. Players on the other hand recieve the capacity for:


You gain an additional +1 bonus to attack rolls when flanking an enemy, bringing the total increase to 4.

subtotal: +6


Available to Fighter class level 13
You gain an additional +1 bonus to attack rolls when flanking an enemy, increasing your flanking bonus to +5.


Like a celestial hound, you are ever vigilant and at home amidst the pack. You gain an additional +1 to your Listen skill, bringing your total increase to 4, and now get a +5 bonus to hit flanked opponents.


Available to Rogue class level 14
You gain an additional +1 bonus to hit with your sneak attacks.

again, subtotal: 6

That gives a variation of anywhere from -5 to -12 effective mob AC used strategically, but to do a direct translation would assume the player is ever as locked in place as most mobs tend to be, and tends to end up as a small amount of variance overall, which somewhat defeats the point. At this point I'd recommend a house rule conflating flatfooted, flanked, and attacks of opportunity, using the philosophy that an outmaneuvering opponent is more difficult to avoid.

lists the conditions for attacks of opportunity

Threatened Squares

You threaten all squares into which you can make a melee attack, even when it is not your action. Generally, that means everything in all squares adjacent to your space (including diagonally). An enemy that takes certain actions while in a threatened square provokes an attack of opportunity from you. If you’re unarmed, you don’t normally threaten any squares and thus can’t make attacks of opportunity.

Being the primary condition of note for that component in regards to this specific notion, and


A character who has not yet acted during a combat is flat-footed, not yet reacting normally to the situation. A flat-footed character loses his Dexterity bonus to AC (if any) and cannot make attacks of opportunity.


Dodge Bonus

A dodge bonus improves Armor Class (and sometimes Reflex saves) resulting from physical skill at avoiding blows and other ill effects. Dodge bonuses are never granted by spells or magic items. Any situation or effect (except wearing armor) that negates a character's Dexterity bonus also negates any dodge bonuses the character may have. Dodge bonuses stack with all other bonuses to AC, even other dodge bonuses. Dodge bonuses apply against touch attacks.

regarding flatfooted.

conflating the three therefore gives us: a flanked opponent in melee range looses it's dexterity modifier and any dodge bonuses, and recives a 2-12 AC loss. For simplicities sake, as well as to keep from making archer mobs more of a laughing stock more than they are, we'll shorten that to

A flanked opponent looses dex and dodge bonuses vs that opponent.

Note that this would bump up the relative benefits of barkskin and equivalents (rangers/arties) and uncanny dodge (barbs, rogues, though obviously for the barb, not so much.)

In conjunction with the first notion, this essentially gives mobs a 'free shot' (attack of opportunity) for outmaneuvering an opponent without penalizing dexed based defenses in typical 1 on 1 tanking scenarios, so that particular portion of the game would remain relatively unchanged, and allow folks to build for variations that excel in a variety of different scenarios on different defensive styles.

TL&DR: basic notion's expanding the dice curve on the low end to replicate multiple attacks, and compressing the high end attainable levels situationally.

Ok, shred it.