hey,

got one question regarding total defense calculations:

NPC companions always tend to prefer the armor with the higher Total Defense rating. I cannot get to the calculation which are behind this atribute though.

For example:

armor with AC 76, MR: 3%, FR 13%, DR 69%, and PR 23% has got Total Defense of 74 and is better than armor with:

AC 92, FR 2% DR 35% and PR 20% with Total Defense of 60.

Can you help me out with calculating the above?

The first thing that comes to mind is to ask whether or not you're figuring in Magickal Aptitude. If these are powerful magick armors we're talking about, the benefits a character gets from them will scale with his MA. In other words, a normal, non-magickal person, or a person who merely dabbles in magick, will only be able to utilize a fraction of the full benefits of armor enhanced by enchantment.

Both armors are magical, one is Mystic Platemail AC 15 (+8) and the second is Dread Armor AC 19 (+31).

The wearer is Gar who has got neutral magickal amplitude.

But the issue here is I think Dread armor has got the better stats, higher AC and Mystic Platemail has got the resistances better only, notably the Damage Resistance of 69% over 35% from Dread Armor.

Yet Mystic Platemail has got the Total defense higher and this is why Gar choses to wear this one if got both in the inventory I suppose.

I thought that maybe it is better after all and I do not understand the item rules correctly thus my question to you.

I'm guessing the Damage Resistance is what makes it better. AC, if I remember correctly, makes enemies "miss" you (or at least stops all damage) sometimes. Damage Resistance stops some of the damage when you do get hit. The damage resistance is twice as good, so even if enemies "hit" (i.e. do damage) a little more often, it's probably better.

As an example, hypothetical numbers: One armor has enemies hit you 50% of the time for 100% damage, so it basically cuts incoming damage in half. Another armor has enemies hit you 75% of the time for 50% damage, so in total it cuts incoming damage by a factor of 62.5%, which is a little bit better. The increase in Damage Resistance outweighs the loss in AC.

These numbers (i.e. Damage Resistance, AC, etc.) are all discussed in the manual, although I'm not sure if a full formula is given for the "total defense" calculation. I do not know the details of how that calculation works, so I'm just guessing with the above.

Also, UniversalWolf is completely correct that the effective numbers will change based on a character's magical aptitude. With a neutral magical aptitude, Gar probably only gets a partial bonus on each set of armor. Note that some equipment requires even higher magical aptitude to get the full bonus, so it may not scale linearly, i.e. it's conceivable that Gar could get the full bonus from a less powerful magical armor but not get the full bonus from a powerful one. For your own character, you can see how much bonus you get by putting the mouse cursor over the armor and looking at the "Magic Power Available" percentage in the box at the bottom of the screen. The percentage tells you how much of the magical bonus you get, based on your magical aptitude. I don't know how to check this number for followers, though.

I always thought that followers choose items according to their base price rather than their properties, and equip the most expensive one. :/ Actually, whoever programmed NPC inventory management AI likely assumed that you would only give your followers items you want them to use, as opposed to treating your party as pack mules; this also explains their habit of wasting consumables of any kind.

Followers most certainly don't care about the item's magick/tech properties in general. (As evidenced by Sebastian happily replacing Studded Leather with Arcane Robes if given such an option.*) You can mouse over magickal items in the followers' inventories (including those on the "equipped items" tab) to see the aptitude-scaled power, any such properties are based on the aptitude of whoever is carrying the item. They will wear stuff even if it has zero MPA on them.

Aptitude-related stat-scaling on magickal items is irrelevant when it comes to their choice of equipment. It does affect Total Defense, obviously, but items with better stats and higher magickal complexity are typically more expensive, so you wouldn't realize your followers aren't looking at the stats at all. And this applies to any type of equipment, so you can probably get a gunslinger follower with a magickal staff as his weapon of choice.

Now, if I remember correctly, Dread Armor costs around 3000 coins, and Mystic Platemail is about twice as expensive, so...

And yes, DR is better than AC. Wearing Dread Armor without anything to compensate for its pathetic Damage Resistance basically means that enemies hit somewhat less often, but when they do hit, they do a lot of damage. And high-level enemies have high enough combat skills to bypass even very decent AC on a regular basis.

* EDIT: And here's specific test results. Sebastian was wearing a whole bunch of other stuff that I didn't bother to take away, but since the only piece that was changed was body armor and everything else remained the same, this probably didn't matter.

Stats with Studded Leather equipped, among other items:
Total Defense: 52 -- AC: 53 -- DR: 33 -- FR: 5 -- MR: 30 -- ER: 0 -- PR: 20

Stats with Arcane Robes equipped (by Sebastian himself, replacing Studded Leather), other items unchanged:
Total Defense: 42 -- AC: 46 -- DR: 18 -- FR: 2 -- MR: 30 -- ER: 0 -- PR: 20

Studded Leather costs around 1000 coins, Arcane Robes cost well over 5000. This is on an NPC with 99 TA. So much for efficiency...

Yeah, I definitely wouldn't trust NPCs to decide for themselves which items to use. They make some really bizarre choices at times.

The key point here may be that less powerful armor can potentially be better armor for a character with low magickal aptitude. One of the key points, anyway.

I remember being confused by all these calculations at one time, but in the end it seemed to me that TD was actually a pretty accurate representation of amor effectiveness. Unless you're looking for something specific like improved electrical resistance, or the two TD values are very close, I'd just go with the higher one.

Remember though, the TD can change if a character's MA changes.

As for Gar, I seem to recall preferring to give him non-magickal bronze barbarian armor. You might want to check the stats on the barbarian armor types.

Well, it depends on how much. Since the Arcane Platemail has double the DR, but only slightly less AC, then yes, it's better. But if it had double the DR and half the AC, it would probably be roughly equivalent (at least in terms of damage per time).

Unless there are other factors that go into whether enemies hit, besides your AC. Does high AC have diminishing rewards? Doubling your AC doesn't actually halve the chance of getting hit?

If you have a more or less balanced armor, or wear other equipment specifically to compensate for its deficiencies, then it isn't really obvious how it works. But if the two stats are far enough apart, then you have something like this:

1. Low AC, high DR: You get hit more often, but take less damage. This means you can take more hits in a row without having to heal, and once you do heal, your opponent has to spend time bringing your HP down again. You can easily get a good idea of your durability this way, and focus more on combat tactics than on keeping yourself alive.

2. High AC, low DR: You get hit less often, but take a lot of damage. This means that a strong enough enemy can take out a large chunk of your health in one hit, and you might not be able to heal all the damage at once. If you're then hit again immediately because your enemy is luckier than you, your health gets even lower, so you get stuck wasting healing items instead of fighting.

These are extreme cases, of course, but since there are enemies that tend to do a lot of attacks per turn (hello, Wolf Cave...), and thus decent chances to score a hit simply due to the attack rate, the lack of damage resistance can become painful quickly.

And, technically, Dodge skill prevents getting hit as well, so it kind of "enhances" AC on its own (and there's no reason not to learn Dodge, particularly if you go for training; who doesn't like seeing enemies kill themselves on a crit miss?). Plus you get AC bonus from high dexterity; on the other hand, for most of the game there's no "natural" way of increasing DR if you're not a half-ogre or a lunatic.

That makes sense. Thanks for the explanation!

FTFY; the rest of that sentence was redundant. ;) Edit: fixed it even further. :p

thanks for your advices, I will keep them in mind during making Gar a killing-machine ;)

Don't forget to talk to Gar whenever you find a new major location. He has special dialogue for many of them.

For example, when your party is in Stillwater, ask Gar if he knows anything about Stillwater.

thanks for the tip!

My Half Ogre Technologist has 90 DR and 76 AC. He's a brilliant, unstoppable brute :-)

Some more precision:

http://www.terra-arcanum.com/forums/index.php?threads/ac-or-dr.18666/


Leonidus, May 4, 2013
#3

Yep DR is way better, and max AC is about half chance to hit, usually.

From my AC chart testing melee:

No melee skill vs AC 0 = 25% chance to hit
vs AC 45 = 20
vs AC 95 = 14

3 melee ranks vs AC 0 = 85
vs AC 45 = 67
vs AC 95 = 46

5 melee ranks vs AC 0 = 125
vs AC 45 = 98
vs AC 95 = 67

Also I have written down:
To Hit = base chance to hit - (AC x 0.5 x 0.01 x base chance to hit) ??
and the ? indicate I was not 100% sure on this.


More precision on the to-hit formula:

http://www.terra-arcanum.com/forums/index.php?threads/to-hit-formula.18764/

He figured out one of the things which was making me unsure. The 0.01 in my formula was actually an irrational number very close to 0.01.