Monster Hunter World: Decoration Categories and Drop Rates

Finally! Gaijin Hunter provided a video for the decoration tables on the drop rates and categories of decorations/jewels from tempered monsters. The video can be found here. Thank you Gaijin Hunter for making our hunting life much easier! All credits to Gaijin Hunter for the translating and gathering the data from the official guide and making the video for us. I decided to create simple tables to summarize the information for everyone's convenience. I travel 6 hours a day so I can only get to read via mobile, this is for personal use as well (I spend a lot of time daydreaming or thinking about my character builds lol).

By the way, you may want to check the main Monster Hunter World guide I am trying to complete here if you have time. 

Author's Note: After the Kulve Taroth update (MHW ver 3.0 onwards), the drop rates changed as T1 can now also drop warped feystones, T2 can now drop hero streamstones and T3 will drop streamstones more often. I don't have formal information on the new rates but I will be updating this or creating a new write-up for it asap. This was to compensate for nerfing flashpods in the update. Bottom line is, hunt T3 for streamstone farming and T1 or T2 still for specific jewels. Table #3 is still usable as reference.

Feystone Appraisal (Table#1)

Monster Hunter World Feystone Appraisal Values (Table #1)

The jewels you get will depend on the type of feystone appraised. Each feystone type has a specific percentage chance of yielding a jewel under a certain category. In the table above, a Mysterious Feystone has an 85% chance of yielding a Category C jewel and 15% for Category B. It will have no chance of yielding a Category A or S jewel. The Elder Melder can produce only up to a Worn Feystone and has a 6% and 2% chance of yielding a Category A and Category S jewel respectively. So if you are looking for  jewels under those categories it would be better to hunt for Warped Feystones than waste your jewels in the melding process. Analyze the table above and refer to the last table below to know under which category your desired jewel is. Category C to S is Rarity 6 to 8 respectively.

Decorations Drop Rates (Table#2)

Monster Hunter World Decorations Drop Rates per Tempered Threat Level (Table#2)

Now, as for the drop rates of these feystones, threat level 1 monsters will have a 0% chance to drop Warped Feystones. The threat level 2 monsters will have a higher chance of dropping a Warped Feystone than Threat level 3 monsters which are the Elder Dragons. The advantage of hunting Elder Dragons though is that they have a higher chance of dropping Streamstones for augmentation. Despite this drop rate, proceed to Table#4 for the math on true % chance to get a jewel under certain categories.

Tempered Monsters Threat Level (Table#2.1)

Monster Hunter World Tempered Threat Level (Table #2.1)

Exceptions (no tempered version) - Great Jagras, Kulu-Ya-Ku, Tzitzi-Ya-Ku, Great Girros, Dodogama, Zorah Magdaros, Xeno'Jiiva

Decoration Categories (Table#3)

Monster Hunter World Decoration Category List (Table #3)

The table above shows under which category your desired jewel is (click to enlarge). So knowing the following data, refer to the first and second table on which Feystone to target and which tempered monster will have the highest chance to drop that specific Feystone.

How To Use the Tables:
1. Choose your target jewel on Table#3 and take not of the Category or Rarity.
2. Look at Table#4 for and take note of the Tempered Threat Level with the highest chance to yield a jewel under your desired category from step 1.
3. Hunt tempered monsters under that threat level from Table#2.1 and pray for the RNG to be generous to you.

Example:
Target Jewel is Attack. Table#3 shows Attack is under Category A.
Table#4 shows that Threat level 2 monsters has a 7.14% chance to get a Category A monster. This is because you need to factor in all the other Feystones that you can also receive and the chance to get a certain category. So the true % chance considering all these, specifically for an Attack jewel, based from the table below will be the 7.14% divided by 22 = 0.32% chance. Wow, that's too sad but don't give up fellas. Also, if you are going to base this on a specific feystone, say for example you got all Warped Feystones, each Warped Feystone will have an 18% chance to get a Category A jewel based from Table#1, dividing it by 22 which is the number of jewels in that category and you have 0.82% chance to get that one specific jewel from that group that you are hunting for.

Combined Percentages to Obtain Jewels per Tempered Threat Levels (Table#4)

Monster Hunter World Chance to Obtain Jewels per Tempered Threat Levels (Table#4)

Conclusion
Still there? All the math is making my head hurt. After a good talk with fellow reddit users, the 26% on the Warped Feystone is indeed misleading. I must admit we all got caught up on this and overreacted a bit. So I do apologize if I got you all even more excited. Tempered threat level 2 monsters will indeed have a higher chance to get Category A jewels. However the percentage chance is only slightly higher 7.14% > 6.66%. For me though, this is still significant and since this percentage is based per reward slot, here's the thing: if your tempered level 2 investigation has 4 reward slots versus a tempered level 3 investigation with 2-3 slots, it would make sense to go for the tempered level 2. There is another computation in which the chances are almost equal by Draycos on my reddit post here. Honestly, at this point I still stand with Threat Level 2 if I want that Category A jewel. In the end it will all come down to RNG and luck. There are still no guarantees but It is really hard to get exactly what you want so any increase in % to get that specific jewel, I think I'll gladly take it. I'd initially take the Feystone with the highest chance to yield my target jewel and worry about the other %'s later. Plus, threat level 2 monsters can be captured which can save you time compared to threat level 3 monsters which could also be more tedious and harder to take down. If I get a streamstone in the process then I'll thank the Sapphire Star for it. I'll save up the threat level 3 quests unless I find the need to go for streamstones. However, if you don't mind whatever jewel you get and want to leave it all to luck, then threat level 3 quests are the way to go as you have a higher chance of getting streamstones and still get the benefits of getting feystones in the process, thus having the most out of the hunting time you committed. As some people said and come to think of it, we are probably going to get burned out hunting threat level 3 all the time. It goes with what you prefer so there is still no right or wrong way of hunting just to make things clear.

Man, this is very useful and utterly frustrating at the same time. Ha ha. I want jewels such as Critical Boost and Attack Jewels only to find them on the highest categories. But at least now we all know what to do to have the highest chance of gaining the jewel we want. What is the rarest jewel you've obtained so far? Let's pray that the RNG will be nice to us. Hope this summary was helpful. Jewel-hunting we go! May the Sapphire Star light our way! 

Author's Notes:
Some are suggesting a text format instead of images for the tables. I will work on that soon but blogger doesn't have a built-in table for easy formatting. I will have to do it manually using html which I do not have the luxury of time just yet. Anyway, fellow hunters have made spreadsheets for your convenience. I really screwed up the initial final %'s so I do apologize for that, the above percentages are more accurate.

For any corrections or if I ever had something wrong, please inform me by sending me an email or commenting below. Thank you!

Links to spreadsheets:
Muskrat01's Version
MobiusOne's Version
Lorgin's Version 
Andrew's Version 

Special Thanks to the Following Fellow Reddit Users: 
My friend Hecaitomixhs for computation corrections, thanks bro!
Muskrat01, MobiusOne, Lorgin for the spreadsheets
Draycos , Meltrix , Drazpa, and epyonmx for the percentage computations and talks.
And everyone else who were willing to help out...

I am glad we are able to work together to provide accurate data. It makes me very happy and proud to be a part of the Monster Hunter World community. Thanks guys.

Check out other written guides:
Monster Hunter World Guide: A Hunter's Tools for Survival (Work-In-Progress)
A Closer Look at Palicos and How to Get All Palico Gadgets, Tailraider Safari
How to Get All Poogie Clothing and Useful Items (Meal Vouchers, Dung, Mega Nutrients, etc.)
Monster Hunter World: How to Get All Mantles and Boosters 

  
Changelog:
March 1, 2018: Published
March 1, 2018 (after a few hours lol): Minor revisions, added usage scenario and thoughts on this, thank you guys for the feedback and inputs.
March 2, 2018: Added Table 2.1 and Table 4, Corrected computations and How-to-use, Added spreadsheets from fellow reddit users, Added Conclusion
March 14, 2018: Modified Table 3 image to display better naming and sort alphabetically.