- I have included the spreadsheet I was using while doing the testing, just in case you want to see it for what ever reason
- my sample sizes are fairly small(~50 runs total thus far of specific testing, but I'm working on expanding it), and therefore could be misleading, please keep that in mind.
- I am not a math major, and I have never taken a statistics class, all of the math I am doing I have figured out my self, and for all you know I am retarded.
- The mechanics I am describing are only true for killing bosses. elites and rares work differently though I suspect the drop chances are fairly similar.
- I only tested act 1, and only the butcher,it's possible that the drop rates/quantities change in different acts (though I suspect that this is not the case)
If you have any questions on how I did the math, or my methods for testing, feel free to ask and I will do my best to answer them.
How magic find(MF) works:
When a piece of loot drops, the game does a single roll which determines the quality of the item (NOTE: I am almost positive there is a second roll done to determine the ilevel)
For a boss, the baseline drop chances for items are:
Orange/green: not a damn clue
the implications of this is that MF will start to be devalued after 173%, as after that point every boss drop should be guaranteed to be a blue or better(though I don't have enough MF gear currently to prove this empirically), and therefore any additional MF would only affect your chance to get yellows.
all that was horribly wrong, I was pretending blizzard would make the system linear, of course they wouldn't.
as it stands, I sadly don't have enough MF gear to get an accurate equation, If anyone has 250+ MF, and would like to help out with the data collection PM your email and I will give you editing access to the spreadsheet.
How Nephalem valor(NV) works:
There are two components, to NV. the first is the standard magic find increase
the second component affects the quantity of loot that drops
the base line number of drops a boss has is 6, and for each stack of NV you will get an additional drop, and with the 5th stack that additional item is guaranteed to be a rare.
Tomes drop on their own loot table, meaning that you cannot get a tome instead of getting an item.
the baseline drop rate for tomes is 50%.
Now NV/MF does affect tome drops, though I don't have a sample size nearly large enough to be fully confident in determining exactly how it affects the drop rate.
at this point all I know is that it certainly increases the chance of tomes dropping, and also appears to increase the number of possible tome drops; as I have seen 0-2 tomes drop with NVx5/108% MF, versus only 0-1 tomes dropping when I had NVx0/0% MF
Other thoughts,not substantiated by testing:
Rares/elites drop 4 items, plus tomes, and while I don't have any data to back it up, it certainly feels like the drop rates (%chance) are about the same as bosses.
For tomes it also feels like even with NVx5/108%MF the drop rate was about 50%, and I never got more than one tome from a single elite.
I hope to get some more free time in the near future so I can further test how tome drops work, as well as test other acts to see if the drop rates are consistent. If anyone would like to help with this sort of thing, especially people who have the ability to easily farm act 3/4 bosses, I would greatly appreciate any and all help. The only thing that I ask is that you be as accurate as possible with your data collection, as tainted data makes for bad science (for example I forgot to put on my 0% MF gear a few times during testing, though I luckily caught my self mid fight most of the time, the 28% MF area in my spreadsheet was when I messed up)
Edited by WTF_is_a_Daveclap, 16 June 2012 - 08:44 PM.