Reasons for not giving advisory opinions:
1. Need for focused controversy: in addition to separation of powers rationale, the ban on AO is also frequently justified by the need to have the judiciary decide only focused, specific conflicts, in which adversaries explore every aspect of the situation.
2. Finality: interest in having judicial opinions be final, and not subject to modification by the executive or legislative branch.

3. Strict Necessity: such issues ill not be decided unless strictly necessary.

–    Except Declaratory judgment: allowed review when they are reasonably concrete. However, Fed cts created pursuant to Art III are barred by the case-or-controversy requirement from deciding “abstract, hypothetical or contingent questions.”