What are some game “secrets” or mechanics you discovered that changed everything?

My third playthrough, I randomly discovered that the arrow of many targets can find invisible enemies by itself. Volo’s eyes or whatever else not working out? NO PROBLEM. Arrow zoom shaka laka. It gets a bit tricky if we don’t see ANYBODY but usually at least one person, is visible. I throw AOE spells or alchemist’s fires to estimate. For the Bhaalists, if I walk ahead and “aura of murder” pops up for me, goodbye bitches. But still, amazing find for me.

Edit add: stacks of scarlet remittance on Rhapsody from Cazador. I just hadn’t paid attention to the description beforehand. Or I did but it kind of downplays the additional features. I equipped Rhapsody for RP reasons on Astarion after killing Cazador. I liked giving my peeps weapons we got after emancipating them this playthrough. But those weapons don’t always have good features or suit the build I have for them. So yeah, I was like okay I’ll swap it out soon. Or don’t even need to as my Astarion is an archer. And then this random bonus option started popping up guaranteeing critical hits after killing an enemy and I was like??? HEH?????!

Then, free cast (if you tap into Illithid powers) + Markoheshkir arcane battery + usual wizard arcane battery + spell slot restoration amulet = 4 6th level spell slots (MWHAHAHAHA)

Using Illithid black hole to put enemies together and then AOE blasting them (the day this occurred to me was the day my evil mastermind laugh was born) Before that/out of battle, minor illusion <3 I was sleeping on this method but it’s so fun

More of a “negative” find; thing to be careful of: I realized that if you put on effects like aid, heroes’ feast, elixir of giants, etc., armour of agathys before the and into morphic pool, they all disappear by the time you get to High Hall. 😭😭😭😭😭 I wanted to yeet myself off where we stood as I didn’t have cloud giant elixirs left, Sharty wasn’t with me and my last save was too far. Thankfully the perks we get from our allies saved everything.