My Lands: Black Gem Hunting

When starting the upgrade of a lab to level 8 it mentions "Chance to generate a potion". I can't find anything about this in the guide or here on the forum. Can someone point me to the explanation that I'm sure is out here somewhere?

there is nothing specific in the wiki from what I have seen. under alchemy it just tells you perfected buildings may have extra features. I have 1 perfected lab and every now and then will get a free mana bottle, have not bothered to keep track but it is not often. if you have many perfected labs maybe it will happen more though

As mentioned, the perfect lab provides a small chance each day to get a free potion (exp or mana) placed directly into the vault. This occurs at the same time as the rest of the perfect events happen, which is once per day (24 hours) at a random time. If the player's vault is full, it will still be placed there at overcapacity.

I am not sure if the effect is a cumulative chance for a single potion or separate instances for multiple potions. I lean towards the former. As like FairyLite, I've not bothered to get many perfect labs and potions are rather weak at my stage, so I don't pay much attention to their generation, but overtime I have seen them populating in my vault.

Perfect labs not at the capital can generate potions still.
It is very similar to the perfect tavern (chance for free scroll) and perfect trading posts (chance for gold surplus)/lumber mills (chance for lumber surplus) in that the % chance is ambiguous.

So, what exactly were you confused about? (I didn't really see a question)
I hope I've helped you in some way.

Cheers

This answers my question nicely; thanks to you both.
(It would be nice if this stuff was in the Encyclopedia....(hint, hint)....)

what is a lumber mills?

woodcutter, tree production

thank you