The piano action or mechanism has thousands of parts. There are many adjustments on a piano action that make sure that all the parts work properly. Regulation is the process of setting these adjustments so that the action can transfer the energy from your fingers into the strings. An action that is out of regulation can lose power, can lose the speed at which it can repeat a note, and can become uneven from one note to the next. Poor regulation can affect the tone of the piano and can prevent you from being able to play softly. Complete regulation can involve many days of work, but there are many refinements of regulation that can be done in the home and in small amounts of time that can keep the action performing at its best.