Banjo G chord (Open D)G major on the 5-string banjo: 0 1 2 0, and 4 more shapes

Frets, string 4 to string 1: 0 1 2 0 (open position)

1. String 4 (D): open, D
2. String 3 (F♯): 1st fret, index finger, G
3. String 2 (A): 2nd fret, middle finger, B
4. String 1 (D): open, D
5. String 5, the short f♯: open, F♯, not in the chord

Sounds: D G B D  ·  G is G, B, D (1 · 3 · 5)

Found in: G major (I), D major (IV), C major (V), G mixolydian (I), A mixolydian (♭VII), D mixolydian (IV)

The 5th string: the short f♯ rubs against the G in this shape, a semitone away: some players let it ring, some skip it.

Open D tuning: f♯DF♯AD, the short 5th string first, then strings 4 to 1.