Judges in Final Fantasy Tactics A2 have slightly different roles than their predecessors from FFTA. At the start of every battle a Judge will appear and proclaim which action will be forbidden for the duration of combat. The clan will also be allowed to inform the judge which of their privileges they would like to use. After a successful battle a Judge may award the clan bonus loot and items.
If a clan member chooses not to abide by the Law System and performs a forbidden action, the Judge will depart the playfield. It is the presence of Judges that allow clan members to be revived and privileges to be used, so violations of the law are not as painful as in FFTA but can still have dire consequences.
Since the Judge is tied to specific clans, the enemy is not affected by laws the way they were in the first game. Whether or not opposing clans have their own Judges and laws to follow is never revealed.