A while back, I made a video on the "rarest
thing possible in Terraria". Woo! While sure, with a chance of 1 in 152 octillion,
that is rare, we can do a lot better than that. In fact, we can go 500 orders of magnitude
higher than that. Well, first, a few definitions. We'll be a bit more specific on the definition
of a single "thing" or "event" in this case. An "event" in this case, has to be triggered
by a single action. We're not finding the rarest-possible Terraria
tick here, we're finding the rarest single "event". This would actually disqualify two of the
things I mentioned in the previous videos - the Rain and Sandstorm occurring on the
same tick - since those are just separate unrelated "events" occurring on the same tick. For this video, any sequence caused by a single
trigger, regardless of circumstance, is fair game. To set up my hypothesized rarest event, all
we need to do is kill a Pirate Corsair without critting in a hybrid Underworld-Snow-Jungle-Corruption-Crimson-Desert
biome using a Grey Zapinator with 99% critical strike chance while in Hardmode, but also
before the Mechs, on Normal Mode, while having the Midas flask on, with 1 tick of bad ladybug
luck remaining to give us -0.0000185 luck, during Halloween, and while also not having
full mana. Yeah. The single trigger of the event is obviously
killing the Pirate Corsair with this setup, and there is a very specific sequence of occurrences
that can occur from this single trigger that happens to be the rarest event possible in
Terraria - and this is that event. So, first, when we kill the Pirate Corsair,
we start with a chance to drop items. We specifically picked the Pirate Corsair
due to its extraordinarily large and rare loot pool, consisting of the Coin Gun, Lucky
Coin, Discount Card, Pirate Staff, Cutlass, Eye Patch, Sailor outfit, pieces of Golden
Furniture, the Gold Ring, and the Buccaneer's outfit, for a total of 33 different drops. Add all 5 hybridizable biome keys, Souls of
Night and Light, Living Fire Blocks, the Hel-Fire, Mech Boss summons, Stars, and the Goodie Bag,
and you're up to 48 different drops. These last 15 drops are a result of the environment
the Corsair is killed in. If you just find the drop rates of all these
items and multiply them together, you get a pretty large number - a lot larger than
the last one, for sure - but it's not as large as we want it to be. To get it to be actually large, we need to
factor in luck. Luck affects drop rates of items, and as such,
we can use it to fine-tune a lot of the probabilities here. Luck in Terraria works like a chance to modify
drop rates - based on your luck, you have a [luck] chance to either increase or decrease
your drop rates within a certain static range. So, for our goal of optimizing the lowest
chances possible, we want "minimum negative luck" - that is, we want to have the smallest
possible chance to roll negative luck's effects, then have negative luck roll the drop rate
as low as possible, just to make the total chance even lower. On top of negative luck decreasing our drop
rates already, the chances of getting a the bad luck roll itself adds even more rarity,
making this whole sequence of events much rarer. The highest-but-still-negative luck we can
get is from having 1 tick of bad "Ladybug Luck" remaining - which has a luck value of
-1/54000 or -0.0000185. That's a 1 in 54000 chance to roll the effects
of negative luck, which is tiny. On top of that, because negative luck decreases
drop rates to within a static range of values, there is another luck roll after that deciding
what to decrease the drop rates to within this range. The chance of rolling the lowest drop rate
within the negative range is itself equal to the base drop rate of the item - that is,
a Slime Staff with a drop rate of 1/10000, if given a bad luck roll, has another 1/10000
chance to roll 1/19999 from within the decreased drop rate range from bad luck of 1/10000 to
1/19999. So, that's a lot of chances! Also, for some reason, this luck roll applies
on every item individually and independently - not on the enemy kill as a whole. You can check it here - RollLuck() is literally
baked into the item drop function for most items. This means that we can add a luck roll of
1/54000, which is the chance to roll drop chance decreases with "minimum negative luck",
and then another roll of 1/X or the item's base chance, which is the chance to roll the
worst drop rate from the range of decreased drop rates. Then, we can change the actual drop rates
to their luck-decreased drop rates, multiply them all together, and we get the FINAL drop
rate for the item. Quite a bit larger if you ask me. Between all of this, the chance for -1/54000
luck to roll the worst possible drop rate for every item the Pirate Corsair can drop,
and have every item still drop, is all of this stuff multiplied together, and totals
to a whopping 1 in 2.24x10^486, or 2.24 unsexagintacentillion for those of you interested in large numbers. That's only like 450 orders of magnitude rarer
than the last video. But, we're not even close to done yet. There are a few more modifiers we can add
to tick up the odds just a little bit. Of those previous 48 drops, six are reforgeable
- three weapons and three accessories. For the Pirate Staff, there are 38 available
modifiers, for the Hel-Fire, there are 25, for the Cutlass there are 40, and accessories
have 19 modifiers, so the chance to get any specific modifier is 1/that number for each
item. After that, we factor in the 25% chance to
not get a reforge at all, making everything a bit rarer, as well as the "bad reforge grace"
mechanic, which has a 2/3 chance to void bad modifiers if first rolled. This "bad reforge grace" essentially makes
rolling something like Broken 3x rarer, since, well, it'll get voided 2/3 of the time. The rarest set of reforges we can get is all
Broken on the weapons, while any reforge on the accessories will be equally rare - let's
just say Warding for now. After reforges, we also count item drop counts. Golden Platforms and Living Fire Blocks always
drop in stacks, and this range is itself determined by a roll. That's a 1/50 chance to roll 129 platforms
in a range of 80-129 platforms, or a 1/31 chance to roll 50 Living Fire Blocks in a
range of 20-50 Living Fire Blocks. Now, money. When you inflict the enemy with the Midas
debuff, you make them drop 10 - 49% more coins than usual on death. The chance to get 49% from that roll is another
1/40 chance. Enemies' coin drops are also innately randomized
from between -20% and +20% of its base drop, inclusive. Rolling +20% on this drop is another 1/41
chance. There are then four successive chances to
increase coin drops further, each rarer than the last. The chance to roll the maximum coin drops
on these chances are 1 in 30, 1 in 110, 1 in 240, and 1 in 420 respectively. Then, not critting with a 99% critical strike
chance is a 1 in 100 chance, obviously. Rolling +15% damage randomization on your
killing blow is a 1/31 chance, but this is affected by luck in its own way, so this ends
up being a roughly 1 in 51,894,000 chance after luck is applied. And lastly, we chose the Gray Zapinator for
a reason, because triggering every effect on the Gray or Orange Zapinator in a single
hit is our final 1 in 5,647,152,000,000 chance. Totaling these miscellaneous chances up, we
get our final chance. So, killing a Pirate Corsair in a hybrid Underworld-Snow-Desert-Jungle-Corruption-Crimson-Hallow
biome during Halloween with 1 tick of ladybug luck remaining with a Grey Zapinator that
procs all of its effects at once but doesn't crit even with a 99% critical strike chance,
and having the killing blow receive +14% damage randomization that negative-luck-replaced
a +15% damage randomization roll at minimum negative luck, and then having that Pirate
Corsair also drop the maximum amount of coins possible, the Coin Gun, Warding Lucky Coin,
Warding Discount Card, Broken Pirate Staff, Broken Cutlass, Eye Patch, whole Sailor outfit,
all twenty pieces of Golden Furniture, Warding Gold Ring, full Buccaneer's set, all five
biome keys that can drop, a Soul of Light and a Soul of Night, 50 living fire blocks,
129 golden platforms, a Broken Hel-Fire, all 3 mech boss summons pre-Mechs, two stars,
and a Goodie Bag despite having all their drop chances decreased to the minimum... is
1 in 2.2 septenseptuagintacentillion... which I think I pronounced correctly. And, I believe that is the rarest possible
event in Terraria, at least under gameplay conditions. Technically you could make a randomizer/probability
machine using stacked faulty logic lamps & AND logic gates that has a chance in 10^10000s
or worse, but that's boring. This should be the rarest one under non-wiring
conditions. A lot of these new chances were brought to
me by thisisabadname, which formed the basis of this video - so thank you to him for that! There was a lot of deliberation going into
this on his end. Either way though, thank you for watching
everyone, and good day and good bye.
