This last-minute recording for Sabbath's second album became their biggest hit. Now you can learn the legendary opening guitar riff to celebrate its 50th anniversary.
Paranoid is often said to be an easy riff to play, but, although there is a grain of truth in this, you'll still need good timing and a solid pick hand technique for a decent performance. In the opening phrase your aim should be to let the strings ring out a little by barring your first finger at the 12th fret, rather than fretting every note on your fingertips.
As you get into the down-picked section notice that all the chords are two-note powerchords. The changes are quick so use your first and third fretting fingers throughout and move your hand in one single, steady movement, without letting your fingers come away from the fretboard.
Tone-wise, dial in a reasonable amount of distortion with plenty of treble. The studio version is double-tracked after the drums and bass come in, so, if you are playing live as the only guitarist, you could try using a fast delay (20-50 ms) set to repeat just once at a low level. This will add the illusion of a bit of stereo space.