Abettor liability arises when a foreseen unintended effect occurs, treating the abettor as if that effect was intended. Liability arises where one abets an act intending a particular effect but the act causes a different effect; the abettor is liable for the effect caused in the same manner and to the same extent as if he had intended that effect, provided he knew the abetted act was likely to cause that effect. The rule equates foreseen consequences with intended ones for purposes of responsibility.