There will be three presidential and one vice presidential debate during the 2012 general election.
"The mission of the nonpartisan Commission on Presidential Debates (CPD) is to ensure, for the benefit of the American electorate, that general election debates are held every four years between the leading candidates for the offices of President and Vice President of the United States. The CPD was established in 1987, and has sponsored all presidential and vice presidential general election debates since 1988." CPD, www.debates.org
Three criteria are used to determine which candidates qualify to participate in one or more of the CPD’s debates:
Candidates must meet all three criteria before being invited to debate.
User Guide: How to Watch NewsHour's Coverage of the Presidential Debate"
All debates will take place from 9:00-10:30 p.m. Eastern Time.