All the units in play will eventally go to graveyard until and unless one side has morale reduced to zero. This may be caused by 0 health, assassination, or sabotage. An unit can leave graveyard to the earlier stages by reclaim or reanimate, and animated has a chance for an unit to avoid going to graveyard. If all units of one side goes to graveyard it is a defeat for that side. However the only exception is assassinate all will possibly cause all remaining cards to go to the graveyard, but the winner is who used the assassination spell.