Can I use "Detect Thoughts" if a companion know the spell?

[Captain Weegee]

I am really curious about this but I don't find any NPC at the moment for testing it.

I know that you can cast "Detect Thoughts" with a scroll on any character while having a conversation, but when Gale as Wizard learns it then he automatically cast it on himself. (at least outside of conversations)

Do anyone knows if it would also work for my character when talking or must I learn the spell for myself?

I just want to know if I should give Gale the spell or if it's useless if I don't let him speak.

[kingsims]

There is a detect thought potion you can craft easily (Not sure if game allows you to use it mid conversation and shows the detect thoughts option in conversation, but if you take it before hand. It lasts until long rest (It won't get overwritten by other potions or elixirs so just chug one after every long rest, with potion of animal speak when you see animals near by.

You can also buy lots of detect thoughts scrolls, and the game will allow you to cast it while in the conversation.

[kingsims]

Need to test the detect thoughts potion option by finding an NPC that has the trigger and removing the scroll from your main party face, and see if the game allows you to chug the potion mid conversation (If so great) Otherwise id buy scrolls and just don't give gale that spell slot its a waste of his spell slots (I believe gale cannot cast it on your behalf. But that needs to be tested to.

The zentarim guy in hideout has 100% detect thoughts, and the guy with the gnolls Rugan.
Tests to do:

+Gale has scroll (No potion or scroll of detect thoughts in my inventory and gale has level 2 spell slot to cast it). - Untested
+Potion of detect thoughts in inventory but not taken - Untested
+ detect scroll on yourself - Works (You just need to make sure you hoard them).
+Gale precasting Detect thoughts on you.- Works (He will lose Level 2 spell slot when used and a spell slot from his total available spells to cast).

[Captain Weegee]

Thank you kingsims, I didn't even know that you can just brew some potions to detect thoughts.

I was able to test it now, and yeah no, it's not possible. You can use the detect though spell only on yourself, altought it's a ritual, it also works while being in a conversation.