Various apparatus and methods for ablating tissue are described therein. In certain variations, a method for ablating tissue may include advancing one or more electrodes, e.g., a first electrode and a second electrode, to or near a target tissue in a subject. The electrodes may be energized such that the electrodes create a plasma arc. The plasma arc generates heat which desiccates or ablates the target tissue. An apparatus for ablating tissue may include an elongate instrument, e.g., a tube or rod. One or more electrodes, e.g., a first electrode and a second electrode, may be provided in the elongate instrument. The electrodes may be energized such that the electrodes create a plasma arc for generating heat to desiccate or ablate a target tissue.