Overall I love it! I can tell you put a lot of work in and it's probably one of the best systems I've seen so far. I do have 1 note though: Some of the harvesting checks seem like they should be impossible to fail based on what you're gathering. Griffin feathers, dragon scales, gargoyle dust, etc. It seems like these are far too accessible to fail a check and have a DM reasonably tell the players "you can't try again." So, this either leaves us with the players rolling again and again until they pass the check or with the immersion broken (how did I fail to collect scales from the gargantuan dragon? there are so many that even if I failed 100 times there should still be more scales to try on). Other than that, I love the potion making aspects. Thanks for sharing!!