As a returning player from 2008 I'd like to know what magic stats are roughly worth these days.
I know that this depends on other gear and what spells you are csting but to have an idea for comparing sake.
Back in the days 2 INT was about 1 MAB, is this still roughly true?
and what about +magic damage?
This was never true.
Ever.
Not even functionally useful (like +X skill is 0.9X acc&atk).
For any real numbers, you'll want to look at
https://www.bg-wiki.com/bg/Magic_Damage
Magic Damage is pretty negligible for anything important. INT is on almost everything anyway.
The BLM forum is up to date on sets, look at that.
I tried reading this but I didn't get a PhD in FFXI.
It's really quite simple. No PHDs needed.
So you have five things that modify magic damage:
ΔSTAT
Mdmg
pMAB/tMDB
Maff
Macc
Your ΔSTAT for BLM is gonna be INT. This determines the spell's base damage. And it's the simple your total INT minus your target's INT.
The larger your INT is over their's, the higher the base damage your spell will have.
However, this is not infinite. Once you hit the cap, any more INT won't change the base damage.
Which is where Mdmg comes in. It simply adds to the base damage. If the base damage is 200 and you have Mdmg+50, then the base damage will be 250.
Simple as addition.
Next comes the RATIO of MAB and MDB.
MAB is simple, it's a % increase to the damage.
Not a hard % like BPdmg or Maff, but a soft %.
So MAB+60 would be a 1.6x modifier to the above 250 base damage.
Or at least it would be if it was a hard % increase.
But due to it being a ratio of yourMAB/targetMDB, you'll find that you'll have a smaller boon than you would think.
For instance, to continue with the example, against trash, likely having only 1~2 MDB, the 250 base damage spell will deal 400~325.
As you can see, just 1 MDB dropped the damage by almost 100.
NMs usually always have large MDB terms, but this is why GEO's malaise is so powerful, dropping their MDB to 1 turns your MAB into a hard % increase.
Maff is almost the same as MAB. It's even now written exclusively as ELEMENT "MAB" +X. It's a straight % increase to the damage after pMAB/tMDB. Fire "MAB" +15 would mean any Fire spells cast will have an additional 1.15x multiplier tacked on.
So our 400~325 would be 460~373, assuming it's fire.
There's also day/weather bonuses, which are another hard % boost.
They happen randomly when you match a spell to the day and/or weather, and can be forced by obis and increased in potency by certain gear.
Finally we come to Macc.
While this will never increase your damage, it will increase your over all damage by reducing resists, which are magical "misses".
There's many resist states, and they all cut your spell's damage by anywhere from 9/10s to 1/5 and even down to 1/16 iirc.
It all depends on your Macc, which is made up of skill, INT and Macc+.
The more you have, the more likely you'll be dealing full damage.
This is why INT is so favorable too. INT pulls double duty, increasing spell damage AND adding Macc in a degree of either 1INT:0.5Macc to 1INT:1Macc depending on your ΔINT. (I like to use 0.75INT for rough Macc comparisons of two pieces of gear. Since ΔINT depends on which mob you're fighting, without knowing their exact INT, you can't say for sure if you're in range to get 1:1 or 1:0.5, so I like to split the difference when comparing pieces of gear.)
Let's look at a simple example, the WKR cape: INT+8 MAB+10
It's giving you between 4 and 8 Macc, and 10 MAB; as well as increasing your spells' base damage. So in order for something to be better than that, ignoring something like the MBdmg cape, since MBdmg is fancy now, a cape would need 6 or greater Macc, 10 or so Mdmg (too hard to calculate without everything else, but 10 should be enough to make up for the loss of 8 INT, depending on your other gear, even 5 could.), and 10 or more MAB.
INT *CAN* be traded off, but you will need both Macc and Mdmg to make up for the loss.
And the less INT you have, the more Macc and Mdmg you will likely need.