(ESO) How Does Metal Extraction Affect Ore Refining Yield?

June 10, 2014

Like much of the crafting system in The Elder Scrolls Online, the Metal Extraction skill (along with its Clothing and Woodworking relatives) is a work in progress. During 1.0, the skill’s stated benefit was to “improve the chance of extracting Blacksmithing ingredients.” It was commonly thought that Metal Extraction also affected the rate at which upgrade materials dropped when refining ore; however, the tooltip for the skill made no mention of this added perk.

In 1.1, the mouseover text was changed to clarify that Metal Extraction (hereafter MX) did, in fact, improve refining yields as well as deconstruction yields:

“Improves the chance of extracting Blacksmithing ingredients and allows the refining of more powerful tempers from raw materials.” [emphasis added]

More importantly, 1.1 seems to have brought a major overhaul in the way refining yields are calculated. In ESO v1.0, even a low-level blacksmith with no points in MX would occasionally get a Tempering Alloy when refining ore. Now, temper drops are restricted by MX rank:

MX Rank Honing Stone Dwarven Oil Grain Solvent Tempering Alloy
0 Yes No No No
1 Yes Yes No No
2 Yes Yes Yes No
3 Yes Yes Yes Yes

In other words, as far as we’re able to tell, MX rank 3 is an absolute requirement for getting Tempering Alloys to drop from ore.

The Test

We wanted to know more about the odds of getting different types of tempers in this new and improved system. To that end, we refined twenty stacks of Ore (half Iron, half Calcinium) at each MX skill level and recorded the results. (Why pool the numbers? We determined in a previous test that there was no significant difference in temper or trait-gem yields between the two ore types.)


Here are the observed drop percentages for tempers and trait gems: (i.e., the percent of the time that a given item dropped when refining a single batch of ore):

MX Rank Stone Oil Solvent Alloy Any Temper Trait Gem
0 17.5% N/A N/A N/A 17.5% 26.5%
1 13.5% 12.5% N/A N/A 26.0% 20.0%
2 12.0% 8.5% 9.0% N/A 29.5% 32.0%
3 13.3% 11.5% 6.8% 3.8% 35.3% 31.8%

The average amount of ingots recovered was 8.5 per batch. This was true regardless of ore type or MX rank.


Obviously, even hundreds of refining operations can give only an approximation of the real odds involved in ESO ore refining. In particular, we still don’t have enough data to determine whether lower-level tempers actually get rarer at higher levels. However, we can be reasonably certain of the following:

  • Additional ranks in MX are required to recover higher-level tempers from ore. No rank, no chance.
  • MX has no effect whatsoever on the amount of ingots recovered from ore. You’ll get an average of 8.5 ingots per 10 units of ore regardless of skill level.

The upshot for miners and blacksmiths is this: your ability to derive value from a stack of ore will vary greatly based on your Metal Extraction rank (and thus, indirectly on your Blacksmithing line rank). At MX rank 0, you’ll get about one Honing Stone per half-stack of ore, which equates to about 1g per unit of ore beyond whatever you can get for the ingots. Under those circumstances, you’re better off selling the raw ore to a wholesaler (one of those “WTB all raw materials” types) rather than trying to sell the products. At MX rank 3, on the other hand, the Alloys and Solvents make it worth your while to do your own refining and sell (or save) the products for yourself.

Ultimately, though, the value of ore depends not only on the MX rank of the person refining it, but also on constantly fluctuating market conditions. To help you make buying and selling decisions on the fly, we’re developing a calculator that makes use of the data from this experiment. Check back soon for this and other ESO gold-making resources.

Data for this post was gathered 5 Jun 2014 to 9 Jun 2014 using versions 1.1.3, 1.1.4 of The Elder Scrolls Online. It may not reflect changes introduced in subsequent patches of the game.

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