Gamers have spent years lobbying for an adults-only rating, arguing it would allow for more mature themes to be canvassed in games while also assuring fewer adult games slip through with MA15+ ratings.

At a meeting of attorneys-general today there was an in-principle agreement to introduce the R18+ classification, however, NSW Attorney-General Greg Smith abstained from the vote, arguing the matter would have to be taken to the cabinet for a decision.

The Home Affairs Minister, Brendan O'Connor, has said the federal government would over-ride NSW and implement the R18+ rating regardless of its decision. However, O'Connor was confident that NSW would get over the line.

"We're introducing a national R18+ classification ... regardless of what NSW chooses to do," O'Connor clarified in a phone interview.

At a news conference following the agreement O'Connor said: “We've now struck an historic agreement and we can move forward to having an adult classification in this country as is the case in New Zealand, the US, Europe and many other parts of the world."

Australia is the only developed country without an R18+ rating for video games.

In a statement released today Smith's spokesman said that before seeking cabinet approval he would “consult with community groups” and undertake “further negotiations with the Commonwealth over the content of the proposed Guidelines”.

However, there was a strong indication that NSW would eventually accept the proposal. Smith said that he "welcomed" amendments made to the R18+ proposal at the meeting today.

If the NSW government cabinet declines to support the proposal it may create a situation where R18+ games can be sold in all other states except NSW.

A spokeswoman for O'Connor said with eight out of nine censorship ministers agreeing to the changes, the R18+ proposal would go ahead with or without the support of NSW. The matter would not be discussed at any future meetings of attorneys-general.

"There is agreement and it's going forward ... at the end of the day it's going ahead. It's being progressed and NSW will do its thing," the spokeswoman said.

A spokesman for Smith indicated that NSW would not stand in the way. "NSW has no intention of being a fly in the ointment," he said.

Greens MP David Shoebridge was quick to round on the NSW Government.

He criticised Smith for failing to formulate a position on the R18+ issue despite indicating the government was pondering it on May 27.

“Greg Smith should stop moralising and start looking into having sensible rules to reflect the material that is out there and at the same time ensure that consumers are properly informed,” said Shoebridge.

“Public submissions were overwhelmingly in favour of the introduction of the R18+ category. To abstain from the vote despite knowing months in advance that it would occur is politically culpable.”

Asked why the NSW government hadn't determined a position on the issue despite it being on the agenda since 2002, a spokesman for Smith said “we have been in power three months”.

He said the government would make a decision at “an appropriate time”.

The video games industry welcomed the in-principle agreement on R18+, which it said had been almost a decade in the making.

"An in-principle agreement for an R18+ classification is a big step towards a robust ratings system that best equips parents to manage their children's access to appropriate content, as well as enables adults the ability to play games of their choice within the confines of the law," said Interactive Games & Entertainment Association CEO Ron Curry.

Mark Bradley, vice president of game publisher Electronic Arts, said he was "encouraged" by the agreement as "the current policy of the Australian government forces arcane censorship on adults who play games ... cuts they would never impose on movies, books or other forms of artistic expression".

The Australian Christian Lobby "cautiously welcomed" the outcome of today's decision but questioned why it was not deferred until the Australian Law Reform Commission completed its review of the National Classification Scheme, which includes examining the classification of games.

“With some tightening of the MA15+ category, the retention of the existing [refused classification] category and no liberalisation of the existing games market, the outcome today is a significant improvement from what had been previously put to ministers for their approval,” ACL spokesman Rob Ward said.

The federal government has been a vocal supporter of the proposal as has the general public and the video games industry, however changing the laws was always going to be problematic as it requires the agreement of all attorneys-general.

Previously it was the former South-Australian Attorney-General, Michael Atkinson, who was blocking the R18+ measure however he has since been replaced by John Rau.

O'Connor said even with an R18+ rating the conditions that had led some games to be “refused classification” – or effectively banned from sale – had not changed.

“There is certain material that should not be accessed lawfully in this country,” he said.

A government-commissioned survey of 2226 Australians released in December last year found 80 per cent supported the R18+ rating.

- with Nino Bucci

The reporters of this article are on Twitter:

@ashermoses@bengrubb@ninobucci