So, I've decided to write a guide to explain these concepts in detail, and hopefully it will help people understand what Magic Find does, what it doesn't do, and why you are getting the drops you do.
My post is based on the fact that Magic Find in Diablo 3 works much like it did in Diablo 2. All my tests and experiences throughout while playing D3 has indicated this, and last week Wyatt Cheng confirmed my assumptions. Magic Find in D2 has been extensively documented, I've played the game for several years, and I'm almost certain that most of the information in this post is correct, except for perhaps minor details.
Quality - refers to whether an item is white, magic, rare or legendary.
Legendary - includes legendary and set items.
As most people probably aren't interested in the mechanics behind it, I'll start with a short overview.
Magic find does:
- most likely work when swapping gear just before the mob dies.
- increase the chance for an item to be of higher quality.
Magic Find does not:
- affect stats/affixes on items.
- affect item level of items.
- affect number of items dropped.
- guarantee higher quality items
Magic Find Basics
- Magic Find is not capped, but there is a limit to Magic Find on gear.
- Magic Find is subject to diminishing returns (confirmed by Bashiok).
- 100% Magic Find most likely doubles the chances of getting a magic quality item from any mob.
- Diminishing returns affect chance of legendary items the most, followed by rare, then magical.
So because of the way diminishing returns work, we get that:
- MF increases the chance of magical items more than it increases the chance of rare items.
- MF increases chance of rare items more than it increases the chance of legendary items.
Magic Find in groups
The amount of Magic Find you have in a group is the average of all players in the group.
Player 1 has 200% MF.
Player 2 has 100% MF.
Player 3 has 0% MF.
Player 4 has 100% MF.
Every player in the group will have 100% MF.
Your group MF is not shown anywhere, your character sheet still shows the MF on your own gear.
Magic Find on followers
Followers can be equipped with Magic Find, but you only receive 20% or 1/5th of his total Magic Find. You can see the amount you gain in your followers character sheet.
Nephalem Valor is not Magic Find
Nephalem Valor provides the player with 15% Magic Find per application, but that is where the similarities end.
- Nephalem Valor has additional effects on most bosses in the game.
- These effects cannot be reproduced by having 75% MF on gear instead of 5 NV stacks.
- NV stacks increases the amount of items that drop from a boss.
- A common estimate is 1 additional item for each NV, giving maximum 5 additional items.
- NV stacks increases the chance of additional rare items, beyond the guaranteed ones.
- 5 NV stacks guarantee minimum 2 rares from a boss.
There are currently 2 bosses in the game that are not affected by NV, Izual and Iskatu. I'm not sure if this is a bug or intended due to ease of access.
I vaguely remember a blue post before release stating that you needed x NV stacks to unlock higher item level or higher quality drops. I'm not sure if this has made it into the final game. Does anyone remember the specifics of this post?
Magic Find on Bosses
There is a lot of uncertainty around MF and it's effect on bosses, mostly because of the new NV mechanic. The information below has not been confirmed, but is a rough guesstimate on it's effects.
- Magic Find affect bosses the same way it affects any other mob.
- With 0 NV, bosses have an extremely low chance of dropping rare or better.
- NV stacks boost the chance of rares significantly.
- Killing any boss for the first time gives loot as if you had roughly 3-4 NV stacks. (1-3 rare items)
- After the first kill, the chance of getting any rare items is very low as you have 0 NV stacks.
- The effects of MF is is very small compared to the amount of blue and 2 guaranteed rare items from 5 NV.
There's a few things I'm uncertain about regarding bosses. I've definitely noted that MF has little effect on the total drops from bosses compared to other item sources, but I do not think this directly related to the MF mechanic, but rather to how drops from bosses are determined.
Assming 5 NV:
Does MF affect the 2 guaranteed rares, that is, can you get 1 rare and 1 legendary? Or is there always 2 rares? If so, that helps explain why MF seemingly has lower effect on bosses.
Bosses also seem to have x number of guaranteed blue items, can MF affect these?
If not, that further explains the seemingly lack of MF effect.
Blizzard has stated that bosses will have a higher chance of dropping rares when killing them for the first time (like normal) on NM and Hell in a future patch.
Magic Find on Chests and Quests
Magic Find works the same way on chests as I described above.
Magic Find probably works the same way on events/quests that give you rewards.
- All item attributes and affixes generated at the time the item drops.
- Identifying an item simply reveals the affixes already determined.
- The player cannot in any way affect the affixes on an item.
The n-roll mehanic
While I cannot guarantee on the details of implementation, I believe this is fairly close to the actual mechanic used in diablo. When an item drops, a series of 'rolls' are performed, where each roll determines an aspect or attribute for the item.
Rolls we can assume are being performed:
- Item type (Sword, Chest, Pants eg.)
- Item level (ilevel61, 62 eg.)
- Item quality (If the item is magic, rare or legendary. This is the only roll affected by MF.)
- Affixes (Actual stats on your item)
And there could be many more, specific details are not important and cannot be guaranteed for. The important part is the separation of rolls for the item quality, affixes and item level.
I would be happy to receive feedback and constructive criticism on the information, structure and layout of this post. I will try to keep it up to date and perhaps it could even become a sticky one day :)