[JP] Christmas in the Underworld Update + New Advanced Quests

As part of the Part 1 Improv-Singularity Repair Support 4 update, there have been changes to the Christmas in the Underworld Main Interlude and the inclusion of new “Advanced Quests”.

Just like the previous Prison Tower, Christmas in the Underworld is now free and only requires completion of Babylonia. Any Rare Prisms spent on the event will be refunded. Rare Prisms will still be needed to purchase further NP copies of Santa Altera. To commemorate this update, there is a Christmas in the Underworld Banner featuring Ereshkigal, Ishtar, and the Christmas Event CE’s.

Christmas in the Underworld Banner

Advanced Quests are a new type of Quests that are permanently added to the Chaldea Gate after meeting some requirement and will reward a unique CE upon completion. No Support Servants can be used in an Advanced Quest and they can not be repeated.

The first Advanced Quest requires London completed and rewards a CE that increases Void Dust drop rate by a multiplicative 5%. Also from the 26th to Feb 2nd, free quests will cost 1/2 AP until completion of 1st time clears for players who have cleared Babylonia and any dust drops will be twice as many.

Inexhaustible Dust Mountain

This Advanced Quest is against Robin, Proto Cu, and Saber Lily and the gimmick is that it further increases the ATK and DEF multipliers when using full class advantage. Sabers will do even more damage to and take even less damage from Lancers etc. Berserkers and Pretenders do not benefit from the gimmick.

Advanced Quest page

Part 1 Improv-Singularity Repair Support 4 page


YOOOOO WHAT A REVOLUTION especially since I assume we’ll be gradually seeing this for every bronze mat with successive Advance Quests.

It’ll be interesting to see how a 5% multiplicative increase ends up effecting drop rates in practice. It’ll probably end up being somewhat better than a 5% increase to the drop rates reported on the spreadsheet Rathus maintains, since it would effect every drop chance, I assume, and per-enemy drop chances we seem to know less about overall.


5%? That’s practically guaranteed!

I want that CE to come as soon as possible.


CE that increases Void Dust drop rate by a multiplicative 5%.

wait they can do that?


Multiplicative 5%

Do we know how that works out in practice? I’m assuming that it’s per mob so it’s not as simple as 63.9 x 1.05 (Charlotte)?

This should help chip away at the 2400 I need :fgo_mhxastare:


:fgo_ereshwoah: :fgo_ereshwoah: :fgo_ereshwoah:


JP players: Still 1-turn the quest with Zerks


We’ll need to wait for testing ofc but I’ve done up some quick maths based on the (almost definitely wrong) assumption that all 4 of the Shadow Servants at Charlotte have the same chance of dropping a Dust. If I haven’t dropped the ball anywhere, the new drop percentage should increase to 66.0% under that assumption, slightly less than the 67.1% you’d get from the straight 63.9x1.05. Even worse it is likely a slight overestimation, but it’s hard to tell without mob-by-mob drop data.

showing my work for peer review

If all 4 relevant mobs have equal chance x of dropping a Dust, to have the current rate of 63.9% means:
1-((1-x)^4)=0.639 → x=0.2248. N.B. this seems pretty sensible, it’s close to gold mat drop rate percentages, which are based on one potential drop per encounter, so it tracks bronze mats have similar drop rates but off easier, more common enemies.
Increasing that by 5% means the new drop rate would be 22.48%*1.05=23.61%.
If each enemy has a 23.61% chance of dropping a Dust, the new chance of acquiring at least one Dust per run is 1-(1-0.2361)^4=0.6595=66.0%.

The page does also specifically mention that only one copy of the CE is available as of yet, with 2nd and higher copies to come later, so that means either 5-slotting this CE at Charlotte for +25% drop rate, or MLB it for a similar boost.


Mats have the same drop rate? Didn’t know that, interesting.

Workings look good to me, I did take Maths to a fairly high level but that was… quite some time ago. I made mistakes in my calculations :fgo_casgilworry:

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That’s better then the gacha! :fgo_bblaugh:

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I want this now, I still need several hundred dust just f0r immediate projects


First you rerun a buster aoe lancer and Archer who have bad batteries then you rerun a buster aoe lancer and archer who have huge batteries. Indian men get no respect or reruns.


Charlotte has a 68.3% drop rate, with this CE, 68.3 * 1.05 = 71.715 it will be 71.715% drop rate.

Hm, not that huge of a increase. Unless additional copies and MLB is very high I’ll only use this when I have no time or no mood to 6 Bond CE it.

EDIT: Guess we can also borrow a future MLB from Support too, which can maybe push numbers much higher.

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Excuse me while I cry and nut at the same time


Looks like an interesting concept, I will be interested to see how frequently they update and how many of these CEs they toss out. Particularly if they hand out more than enough to mlb it once, could help resolve some of the bad in resource farming.


It’s going to be more beneficial on mixed nodes that also happen to drop void dust. Like the other egg node in LB4.

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So what I’m getting from this is that the drop rate buffs weren’t enough so, rather than buff them again, they decided to make us waste CE space instead

At least they somewhat addressed how expensive the Main Interludes were. It would have been nice to drop the NP copies’ cost too, if not entirely. Still doesn’t include Servant Coins, but it makes these Interludes decent alternative to welfare reruns now, especially since they haven’t been consistent about them yet


The drop rates were buffed? This shit is still ass.


Not on NA


Who are you? What did you do to my FGO?