Reply speeches are only in Senior debates.  Each team gives a reply speech after the substantive speakers are finished.  Each team has one reply speaker.  Only a 1st or a 2nd speaker can be a reply speaker; a 3rd speaker cannot do the reply speech.  The reply speech should identify the major issues of the debate.  An issue is an important subject that both teams have or should have dealt with during the debate.  The reply speaker should not use the reply speech to rebut, but should summarise the major issues and explain why his or her team was more convincing on the issues.  For example, perhaps his or her team were consistent on the issues, proved the links, proved the points with better evidence, showed why the issues were relevant to the debate etc.  A reply speech should last for 3 minutes.  Reply speeches are given first by the negative team and then by the affirmative team.