Spell stones

question
#1

I was reading uo on vds as my group was building there characters on session 0 .

With spell stones do you need to roll to hit ? Or do they just happen when used ?

If you do need to roll what stat do you use ?

#2

I think it’s always fun to make a roll out of the idea(s) your players have. I’d say have the stones prompt a roll (in most cases).