An adjustment mechanism for a stringed instrument in which the stringed instrument comprises a guitar body, a bridge supported by the guitar body, a saddle affixed to the bridge, a neck pivotably coupled to the guitar body, a fretboard supported by the neck, a nut affixed to the neck adjacent a headstock, and a plurality of strings extending between the nut and the saddle. The nut substantially forms a pivot axis for at least the fretboard, and a heel end of at least the fretboard is pivotably about the pivot axis, via an adjustment mechanism, for adjusting an action of the strings. A method of adjusting string action of a stringed instrument is also disclosed.