How does magic find work?

Question

So I found some gear that has the stat "increased magic find".

What is this "magic" that I can find? Gems? Potions? Some other form of loot?

I need to know what it does before I can decide if it's a stat worthy of my mighty character.

Answer 1

Magic Find improves the chances that you will find magic/rare/set/legendary items. It also affects the number of affixes that a rare item will get [source]. It does not affect the item level of the loot that is dropped, which affixes the item gets, or the random values associated with those affixes. It does not affect gems or potions things or other types of non-equippable items. It does not affect the amount of items that you find (only their quality).

Here's a recap of how magic find works.

Magic Find has always been one of the most popular item attributes in Diablo. Magic find helps increase the probability that a higher quality item will drop from monsters.

• Magic Find helps increase the likelihood of Magic, Rare, Set and Legendary items dropping.
• The Magic Find attribute can be found on any items that are high enough to support the affixes.
• Magic Find is based on a percentile increase.
• You get 20% of the MF found on your follower (source)
• When played cooperatively items drop separately for each player. This means each player sees their own loot and not loot that has dropped for the other people in the group. When picked up and dropped on the ground or traded the items obviously become visible to the other players as well.
• Players will find stacking Magic Find gear more difficult than Diablo II due to the sacrifice of other important attributes.
• Topaz gems will add Magic Find when socketed into a Helmet.
• There is a 300% cap on Magic Find. Magic Find attained from Nephalem Valor is unaffected by the cap, so you can effectively get as high as 375%.

Keep in mind that your chance of getting a certain item type is multiplied by your increased magic find. For example, if you have +100% magic find, then you won't find magic items all the time. Instead, if a legendary has a 0.1% chance to drop off of this particular monster, then it will instead have a 0.2% chance to drop (an extra 100% of it's base chance).

Answer 2

I read through all of that post and I was still confused, the question is asked as your thinking but the dev reads and answers it as bwarner is thinking. The key I realized is that he said it works "exactly as it does in D2." D2 has been out for 12 years resulting in a wealth of information.

A search for MF in D2 and viola: Diablo 2 Wiki - Magic Find

The way it makes most sense to me (simplified) is like this:

1. A monster generates with all the loot it is going to drop attributes and all.
2. You kill that monster.
3. A "dice" is rolled for each item to be dropped with a percent chance of that item being the legendary version.
4. If that roll does not land a legendary item, then a "dice" is rolled with a percent chance of that item being the set version.
5. If that roll does not land a set item, then the process is continued for rare and magical.

Magic find increases the percent chance of the "dice roll." 0.1% chance to find legendary +100% MF = 0.2%

This wiki explains that the amount of bonus is less for legendary < set < rare and equal for magic. So the increase in the explanation above would be 0.177% instead of 0.2 (read it, theres a graph.)

As far as the attributes of the items, i'm guessing they have their own tiers and chance of each with a similar rolling process when the item generates with the monster.