The Coalition has held government in NSW since 2011.

In NSW, a party or coalition must hold at least 47 of 93 seats in the Legislative Assembly to form government under the Westminster system. This is known as a 'majority government'.

A hung parliament occurs if no party achieves a majority. A major party may then join with independents or minor parties to form government. This is known as a minority government.

Analyst Dr Kevin Bonham reported on his blog that if the election was held on March 6, Labor would have won approximately 44 seats.

If this occurs after March 25, Labor will need to join with at least three independents or minor party members to achieve government.

Opposition leader Chris Minns has said he did not plan to make deals with independents before the election.

"My colleagues and I are running for majority Labor government and I'm not going to do any deal before the people of this state have actually had their say," he said.

Premier Dominic Perrottet told voters on March 6 that "it's not time to vote independent" as Labor's lead narrows.

A minority government is a realistic outcome - but what does this mean for your vote?

Much of the election's outcome will come down to marginal seats - electorates where there is a narrow margin between the Labor and Coalition candidates for the seat.

According to election expert Antony Green, these seats' margins range from Kogarah and East Hills - with just a 0.1 per cent margin to Labor and Liberal, respectively - to Parramatta, with a margin of 6.5 per cent favouring the Liberal party.

Other key seats are those which Labor must win to form a majority government if they miss any of the more marginal seats. These seats include Oatley, Camden, Ryde and South Coast, all currently held by the Liberal party.

There are 29 key Legislative Assembly seats in this election, according to Mr Green.

Key seats held by Labor

Key seats held by the Liberals

Key seats held by the Nationals

Key seats held by independents and the Greens