if you have the purity perk and try to create certain potions the game automatically chooses which effect, im not sure but i think by gold value. so if you want to make a potion but the ingredients share a more expensive poison effect the game automatically chooses the poison. so often you are unable to make the desired potion even if you have selected it under the desired category in the create potion menu. unless this is an intentional feature (and i don't understand why it should be) it definitely needs to be fixed.

You have to make sure the ingredients you are using does not appear in more than one common recipe. Otherwise what you describe will happen. Uesless perk in my opinion.

I think it's far from useless. If I am making a poison, I sure do not want it to be healing the target. OTOH if I am making a Health pot, it kind of defeats the purpose, when it is killing me as well.

But you can avoid it by using ingredients that only share one common effect. It's called selective recipes.

yes, you can avoid by doing that. but in many cases i'm trying to make as many (type) potions as possible. however even if two ingredients are listed under "fortify destruction," for example, if those two ingredients share a common, more expensive effect, the game automatically 'chooses' that effect. this is a problem, but when you are correctly creating potions/poisons i think the perk is awesome. i don't know why it is designed this way and i feel like it is an unintentional feature that hinders alchemy. which should not be the case if you are a master alchemist.

never found it useful tbh

Oh, is that what it's called? Well, thank you for the very persuasive and detailed explanation.

I have only had one character that was even remotely strong in Alchemy. It seemed a necessity to have this, at the time. I just assumed that it removed the weaker of the two.

I am interested in this more as I just started a new char that will be heavy in Alchemy. I may need to rethink the application of this.

don't let this thread fool you, purity is an awesome perk! the thing is when you mix two ingredients that share both a positive and a negative effect, usually they both appear in the final product. i would never make a potion/poison like this unless i was leveling (in which case it is actually desired), and i definitely would never use it (in most cases...). purity just automatically 'purifies' the potion to have only the one effect which is calculated by gold value. in most cases this leaves you with just purely the potion you want and no side effects. however i don't think it makes any sense that it always defaults to the more expensive effect. it should always default to the effect of the category under which you choose it. so both of the ingredients will appear in two lists. it should just create the effect under said list. i'm just confused because it doesn't make any sense and should not be a feature imo. please fix this!