And as Parliament's privileges committee report this week into the use of parliamentary privilege where MPs believe rulings of our highest courts are wrong shows, the judiciary can act as a check on Parliament, and vice versa.
So given the importance of appointment as a QC, is the process for deciding who gets to be a QC fair?
There are always aggrieved unsuccessful candidates after every round who view their credentials as better than, or equal to, those candidates who were successful, and concerns have been raised that a disproportionate number of QCs are in Wellington.
I hasten to add what most people don't know, which is that recent amendments to the Lawyers and Conveyancers Act 2006 and Crown Law's Queen's Counsel - Guidelines for Candidates, issued this year, state that in general, only lawyers who are not part of a firm and who practise on their own can be QCs. So I have no horse in this race.
This differs from the situation between 2008 and last year, when as part of the then-Government's drift towards republicanism, Queen's Counsel were referred to as Senior Counsel, and could be members of a firm rather than solo lawyers. But the National Government restored the title of QC.
Appointments are made by the Governor-General on the advice of the Attorney-General and with the "concurrence" of the Chief Justice. Lawyers are invited to apply.
Before making a recommendation, the Attorney-General must consult the Law Society and the Bar Association on the candidates for appointment.
Criteria for appointment include demonstrated excellence, knowledge of the law, oral and written advocacy, independence, integrity, honesty and leadership.
But those who are unsuccessful find it hard to check whether they have been treated fairly because the discretion given to the Attorney-General and the Chief Justice is large.
A previous Attorney-General considered abolishing QCs in 2000 because the process could be seen to unfairly privilege those who impress the Attorney-General and the Chief Justice.
Most of the rest of the world does manage to identify top litigation lawyers without using the Queen's Counsel designation. But as law becomes ever more specialised, it is clear that those who specialise in litigation and are very good at it should gain recognition.
But if so, why not recognise barristerial excellence in other legal specialties? The previous arrangement, where any practising lawyer could in principle be appointed as Senior Counsel, went some way to address those issues, although most of the SCs appointed were litigators.
The current arrangement is that, infrequently, the Crown will continue the established practice of appointing as QCs lawyers who are not otherwise qualified - for example, because they are not barristers sole - but whose contributions to the law warrant recognition.
The current Attorney-General and Solicitor-General were made QCs last year, and Clerk of the House of Representatives David McGee, QC, was appointed in 2000, as was former Supreme Court Judge Sir Kenneth Keith, QC, in 1995.
QCs appear to be here to stay (and probably rightly so), so it is important that the appointment process is more of a science than an art, and transparently so, given the importance of the Queen's Counsel designation in legal problem solving and for checking the executive and parliamentary branches of government.
Mai Chen is managing partner of Chen Palmer lawyers and an adjunct professor at the University of Auckland business school.