Abstract: Methods of jarring include communicating between a surface command device and jars in a drill string, the drill string composed of spaced apart jars positioned in a corresponding plurality of wired and/or wireless pipe sections. The methods include selectively controlling charging, firing, amount of force, and/or direction of force of the jars using digitally-controlled surface command devices. One method includes firing a sub-set or all of the jars in a controlled manner and determining depth of a stuck drill string section through analysis of behavior or performance of the fired jars. Other methods include subsequently firing one or more of the jars again below the stuck drill string section. Other methods include selectively firing, using digital signals from the surface command device, jars sequenced in time so that their forces meet in a constructive or destructive manner at a preselected point in the drill string.