[Question] about item drop rate

[Demon]

DemonSlayer [Demon Cry] (+20% drop)
Bishop [Holy Symbol] (hyper skill +30% drop)
Accessory (+xx% Drop)
Family buff 1.2x drop
winter +50% drop

when on 2x drop coupon , which no stack ?



eq 60% drop rate [earring 20% + ring 20% + ring 20%] , will become 60% ? or 20% (no stack) ?


if i killing a boss , what drop buff should i do ? (below thoes thing)

2x coupon
demoncry +20%
hs +30%
accessory drop +60%
family 1.2x drop
winter +50% drop



pls help ..

[Mandalay]

The general rule is that two of a kind in the same Inventory tab cannot be stacked. You can't stack two Cash Shop coupons, Winter drop and Easter drop, Familiar and Winter drop, and so on and so forth.

I believe you can't use Family buff and Winter drop. The last time I tried Family + Easter Egg 2x drop, I got a message saying "One or more events are already in progress." So I had to cancel the Family buff.

As for the second question, all those drop rates will stack.

[MountLag]

Drop rate = CashShop X DropBuff X AlchemyBuff X Potential X SkillBuff

Only 1 cash shop coupon gets applied.
Only 1 normal drop rate buff can be active at a time. Familiars, consumables (easter egg), and family drop all fall into this category.
Skill based drop rate buffs should stack with each other multiplicatively.
Alchemy buff is wealth acquisition potion.
Potential probably stacks with itself additively.