Complexities abound. For example, the Family Court can rule that money in KiwiSaver or superannuation is part of a split.
If the money can't be accessed, it may have to be accounted for in other ways, such as the other partner getting a greater share of the house in lieu of the locked-up money.
Sometimes money is squirrelled away in trusts that the courts rule to be "shams".
In the case of Clayton v Clayton, Melanie Clayton claimed assets held in trust by her ex-husband were in fact joint property and should be split. Unravelling the situation resulted in many thousands of words being written.
The case illustrates the trend of courts at all levels trying to ensure that assets accumulated by partners during long relationships are shared equitably, whether they are held in trusts or not, says Andrew Watkins, special counsel at law firm Duncan Cotterill.
Sometimes "assets" can simply be difficult to value, such as goodwill in a business, and couples fight their way through the courts for years.
There can be nasty surprises. Student debt, for example, is not always relationship property and there have been cases where couples repaid one debt first, then split, leaving one partner with a big debt.
Rules that allow for compensation for economic loss when one partner has given up a career aren't fair if you can't afford to enforce them. Section 15 of the act, which allows for one partner to get more of the assets than the other to make up for their reduced earning power, is the source of much embitterment.
With any law there are always cases that fall outside the usual, and when it comes to a demand to "hand over the money, honey", a big fight can ensue.
Child support is another can of worms, and to add to the potential confusion, a slew of changes have just come into force in this area.
The Child Support Act ensures financial support is paid by parents who either don't live with their children or share the care. The Child Support Scheme is managed by the Inland Revenue Department (IRD) and uses a formula to work out what parents who have split pay for the cost of bringing up their children.
Child support is only mandatory in cases where one parent receives sole parent or similar benefits from Work and Income. Parents outside the Work and Income net make arrangements between themselves. If they can't agree, the IRD can step in. More details of the basics of how child support works can be found here.
There have been two major changes to the Child Support Scheme in the past 14 months.
In 2015, the 20-year-old formula was revamped to take into account, among other things, children from new relationships. Then in April, the upper-age limit for child support was reduced to 18 years, and the penalties for late payment were made slightly less onerous, splitting it into a two-stage process where the total 10 per cent fee isn't charged until eight days after the due date.
Incremental penalty charges have been reduced and write-offs are now easier. And there are more grounds for administrative reviews.
When negotiating your divorce settlement, it is important to designate who will be the owner of the life insurance policy.
About 137,000 parents are paying child support. Under the changed rules about 33,000 will pay more and 46,000 will pay less. The rest are unaffected.
It's difficult to track down large numbers of case studies relating to child support through the IRD or Ministry of Justice. Pressure groups publish case studies, but they're probably not a fair representation of the types of complaints.
"Belinda" made what is a common complaint. She said the father of her children had set up a limited company with his new wife as a 50 per cent shareholder.
The ex-husband was declaring an income of $20,000, when he clearly earned far more than that, she believed. Belinda complained to the IRD that she was the one paying child support when her former husband lived in a household earning far more than she did.
Nothing is ever black and white when it comes to families. In one case heard by the Office of the Ombudsman a mother complained that the father of her disabled child who was on a good salary should be forced to pay his arrears by way of an overdraft or loan, rather than be allowed to claim that he couldn't afford to pay from his income.
There are other financial issues for splitting couples to consider outside property and child support. For example, says Ed Saul, director of Intelligent Life, what happens if your ex-spouse dies or is disabled and can't work?
For this reason it makes sense, and is sometimes written into agreements, that the supporting spouse, or both partners, should carry a life insurance policy so that any children are still provided for should a parent die.
"When negotiating your divorce settlement, it is important to designate who will be the owner of the life insurance policy," he says.
As extra "insurance", says Saul, a provision can be included in a relationship split agreement that if the beneficiary is changed or the policy lapses, you or your children would be entitled to a portion of your ex-partner's estate of the same amount as the cover offered by the insurance policy the ex was supposed to retain.
Beware as well, says Richard Broad, of Perpetual Guardian, that wills, trusts and relationship property matters are intertwined.
If, for example, you want money in a will to go to someone other than who it would go to under the Property (Relationships) Act, then you need a "pre-nuptial" agreement to complement the will.
When one party dies, the children can often be left high and dry.
