Vice-President Law and Legal Definition
The U.S. vice-president's primary duty is to succeed to the presidency in the event of the resignation, removal or death of the incumbent president.
Under the Constitution, the Vice President is President of the Senate. As President of the Senate, the Vice President is nominal head of the United States Senate. In that capacity, the Vice President is allowed to vote in the Senate, but only when necessary to break a tied vote. This is only overridden when the Senate is conducting an impeachment trial against the president.
Pursuant to the Twelfth Amendment, the Vice President presides over the joint session of Congress when it convenes to count the vote of the Electoral College.