It means the next government will be made up or more than just one party.
Here is a beginner's guide into what that means - and what it might look like.
Winston Peters' role
New Zealand First leader Winston Peters may, again, have a role in forming the next government.
In 1996, Peters worked with National and in 2005 and 2017, he worked with Labour.
Peters is not National Party leader Christopher Luxon's first choice when it comes to making a deal - but has said he will make that call if he needs to.
Luxon's ideal situation is to form a two-party coalition government with ACT.
That could happen - as the preliminary election results show they just have enough seats to govern alone - but special votes could change that.
If ACT or National lose any of its seats as a result of special votes, Luxon will need to pick up that phone and give Peters a call.
What is a full coalition?
A coalition is when two or more parties sit together at the highest form of government - the Cabinet.
They make a pact to agree on all things the government decides to do, including the unforeseen.
There are also specific things they agree on will happen at the outset - while the coalition exists.
Confidence and supply deal
A less intimate option is a confidence and supply deal - but that only guarantees two things for National.
It means the minor party (NZ First or ACT) agrees with National whenever MPs are asked if they have confidence in the government.
It would also see them agree to vote for supply, also known as the Budget.
There are usually some policy wins agreed on at the outset of a confidence and supply deal - but everything else is up for discussion during the time the government is in power.
With this sort of deal, the minor parties are in a position to block National's plans.
It is often associated with a 'minority government'.
Labour's Helen Clark ran minority governments in 1999, 2002 and 2005.
Meanwhile, Labour's Jacinda Ardern signed a confidence and supply agreement with the Green Party following the 2017 and 2020 elections.
Te Pāti Māori had them with the National Party in 2008, 2011 and 2014.
Any other options?
Another option is possible.
National signed a memorandum of understanding with the Greens in 2011. It outlines some of the things the parties agree to work together on.
This could be an option with New Zealand First this time around - but there would be no promises of votes on confidence and supply.
Luxon speaking to both parties
On Monday morning, Luxon confirmed to Morning Report he would be speaking to both ACT and New Zealand First in the next three weeks while special votes were counted.
He said all negotiations would be done confidentially and behind closed doors.
"We are not doing this by negotiation through the media," he said.