You must have experienced it when you do processing, there's a time when you see those irritating "Processing is not going as planned" message often. You may have wondered, how the processing success rate works?

Here I try to explain it a bit based on data and information I have gathered around. I know at the end of the day, it comes to RNG but don't forget with probability there's also this kind of law and processing is definitely one of activities that can take advantage of that. It's probably not entirely 100% accurate but it should be close to and totally better than knowing nothing.

What's the default success chance of processing item?
The base chance without using any cloth or item is around 2/3, let's round it down to 66% for now. Meaning that when you process 100 stuff, on average you should succeed with only 66.

What items that can buff my processing success rate?

Here's generally the list of item that can increase success rate (not listing item from event):

Silver Embroidered Craftman's Cloth +0-5 (*6% - *40%)

Maid Outfit (+3%)

Couscous (+5%)

Alchemy Stone of Life (+5% - 25%)
 

Notice that only the cloth that has * on it, not +. It means that it has a multiplicative bonus while the other items have additive bonus, and it multiplies from base chance. Let's have an example, if I have Silver Embroidered Craftman's Cloth +3 (*22%), Sturdy Alchemy Stone of Life (+11%), and Maid Outfit (+3%), then my overall success chance would be :

0.66 * 1.22 + 0.11 + 0.03 = 0.9452 or around 94.5%

Can I hit 100% success rate (or beyond)?

I wish we can, but no. It's capped at 95%. If you've reached that number, adding more buff won't do anything and it's just a waste. In my example, I have 94.5% so adding couscous will only add 0.5% to reach 95% and imo it's a total waste, 94.5% is already enough.

So in short, this tip should be telling you to do the math first, don't waste resource to try maximize success rate when there's clearly a cap.

If you have anything to add or want to correct things, or even have any questions, let me know on comment.

Source:

https://docs.google.com/spreadsheets/d/1dX_oOuu2FmxSy0CufdBD0gEeeBaqEICNrm4cqtHiwqY/edit#gid=1675529550

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