How does luck actually increase the drop chances?

[Jostabeere]

So I was curious. You have a formula on the wiki and whatnot, but I still cannot figure out the exact numbers.

So if I understand, the base luck of a player is 0. 0 represents the standard drop rates. For example I take something that drops with 25%, aka any master mode pet or mount.

Now if I increase my Luck with a potion by 0.3, a gnome by 0.2 I have 0.5. Does this make my 25% drop chance into a 37.5%?
Now torches have a positive score of 1. So basically if placed right they double my drop chances. With the 2 factors above I have 62,5%?

I ignore Ladybug luck as I am unable to "touch" any of them spawned in the wild, as left or right-clicking them does nothing. Killing any also does nothing, I don't receive any buff/debuff.

 

[Haxor]

First, I'm gonna assume (as you did) that the potion luck gets added just like the other luck sources since in the wiki page it says "Maximum: +0.3 / Minimum: 0 " for luck potions and I don't understand what luckPotionAmount is exactly or why we divide it by 10 in the formula.

If your luck adds up to +1.0 as in your example, it means there's a (100*1.0)% chance (so just 100%) that the 1/4 (25%) drop chance will increase. What the resulting chance will be is random and each possible resulting chance value has the same chance to happen as any other, and it will in the range be between 1/3 and 1/2. That is between 33.3% or 50% or between 1/X-1 and 1/(X/2) where X is 4 in this example. That doesn't technically mean that the drop chance will be the average of 1/3 and 1/2 (which is 5/12) but rather that, on average, the drop chance will be 5/12.

Notice how since the range is between 1/X-1 and 1/(X/2) and not between 1/X and 1/(X/2) that average wouldn't be 37.5% because for the average we use 33% and 50% rather than 25% and 50% so, on average, the drop chance is slightly higher than multiplying your normal chance percentage by 150% (when you have 1.0 luck).

Since the chance of having your chances increased is equal to your luck (0.2 luck would mean there's a 20% chance the chance being calculated will increase), the average increase in that chance will be equal to the increase you would have with 1.0 luck times the actual luck you have.

Your luck can go past 1.0 but it won't do anything after it so there's no doubling your chances. Best you can do is get them slightly higher than 150% the normal amount with ≥1.0 luck.

Do not confuse torch score with torch luck. If your torch score is +1.0 it doesn't mean your luck increased by that amount. If you read the notes below the torch luck table you'll see that if your torch score is 0 or less, it won't affect your luck. If it's between 0 and 1 (non-inclusive), your luck is increased by 0.1. And if it's 1 or more, your luck is increased by 0.2.

I also don't understand the lady bug buff but I'm guessing it's invisible.

BTW, luck affects more than just drop rates, according to the wiki.