Thought this would be an interesting poll. I am trying to work my way up to using four fingers on my non-fretting hand, so I put myself down for 4.
Usually just two, index and middle, sometimes thumb (pluck not slap), but all of them when I'm doing chordy things.
It depends on how the music is written. If there is a separate bass line and a melody I will play with my thumb on the bass line, and one to for three fingers for the melody. If there is only one line I will play with two or three fingers depending on the line.
There are songs I play with just my thumb, others with two fingers, others with three fingers, some with thumb and two or three fingers. That's either all of your options or none of them.
Index and middle, though on the couple of occasions when my fretting hand has cramped up, I've used my Ring and Pinky until I could stretch my hand out.
From 1 to 4 (the fourth being the thumb). I have tried to use three fingers for most of the material we play but sometimes two sounds and feels better (likely the way the song was played originally), sometime one finger for a strong attack.
Mostly forefinger and middle (that's where my calluses are), but also thumb and for a couple tunes ring finger. "White Rabbit" comes to mind.
I use 4 if you count the thumb as a finger. Most often just my index and middle fingers. But I occasionally use my thumb for slapping and also in a similar way a classical guitarist does. And for some parts I incorporate my ring finger using Billy Sheehans three finger technique for example. Can’t think of any parts where I pluck with my pinky finger. On my fretting hand I use everything. 4 fingers obviously for fretting but on 4 and 5 string my hands are big enough that I can use my thumb to mute the lowest string. Which is sometimes necessary to play parts cleanly when I’m using my right thumb to pluck a string.
I'm assuming you mean at a time. I pluck with my thumb alone for some country, use index and middle for most of my fingerpicking playing, but don't rotate between the three. I use a pick to so I never felt the need to develop picking with three or four fingers.
I have been trying index, middle, ring to cop White Rabbit properly. My ring finger is not really up to the task yet.
Changed to four after realizing that even though the pinky doesn't really get involved, the thumb does. Here comes the THUMB-doo dn doo doooo!
Mostly two fingers, but sometimes use the soft side of the thumb in non-slap way, particularly for chords and tenths. Also some use of the fourth finger...sometimes to start or complete a phrase, sometimes in alternation with the second finger, on steady eighths, sometimes on chords. There is something about the way my fourth finger works that lends a percussive attack, which I sometimes utilize for effect or variety in phrasing. I should add that I'm left-handed, and any evidence of right-hand dexterity is always a pleasant surprise.