A blockbuster video game which sees players act as terrorists and shoot up civilians has sparked calls for the Australian classification system to be cleaned up.

The eagerly-anticipated Call Of Duty: Modern Warfare 2 blasted past $US300 million ($325 million) in sales on its opening day, blowing away even Hollywood films to become the highest-grossing entertainment launch ever.

The game, which uses realistic graphics to show a first-person view of terrorists shooting people, has been rated M (17+) in the United States and 18+ in the United Kingdom, but it has been given a MA15+ rating in Australia.

Australian Council on Children and the Media (ACCM) vice president Elizabeth Handsley wants the board to rethink its decision and says it should be banned.

"What we've got here is something that appears to be a mistake - something that needs to be corrected," she told ABC News Online.

"This material should not have been rated MA15+ - there seems to be a consensus for that.

"The problem is that this game is available at all. We need to focus on that and on the effect it will have on those younger children whose hands it falls into."

Advanced gamer Jeremy Ray, also known as Junglist, has played MW2 all the way through as says it is "entirely full-on".

"When the terrorist level starts you step out of an elevator, the memorable line is one of the guys turning around to you and saying 'Remember, no Russian,'" he told ABC News Online.

"Then all of you bring your guns up and you just unleash on an entire crowd of people. There's people screaming, some people trying to put their hands up to surrender, but everybody gets mowed down. You can choose not to shoot, but you can also choose to throw grenades, kill security guards.

"You eventually come up to a balcony where you're looking down on a massive crowd of people and then you can unleash of them. Then you have to take out a SWAT team with riot shields."

Ray says the terrorist level fits into the context of the game, but as a former reviewer for ABC2's Good Game, he is well aware of the inconsistency of what gets classified and what gets banned.

"It's almost random; There's absolutely a lack of consistency and there has been for years," Ray said.

"I've seen it in the last three years, reviewing games every week, I've seen an example of the inconsistency about once every three weeks.

"Generally, if the game has a backing of a big company, it tends to get through."

Ratings clean-up

The Australian gaming industry has been calling for an R18+ rating to cater for adult gamers and the release of this game has reignited that debate.

"Having no R rating encourages OFLC to rate games MA that should be R (e.g. MW2?)!," robdmoore said on Twitter.

"Game Classification in this country is FAIL," walmillard tweeted.

The Gaming Developer Association of Australia president Tom Craigo, who has not yet played MW2, agrees.

"Not having the R18+ removes options for the board - it's either MA or it's banned," he told ABC News Online.

"There's this problem of shoe-horning where games get put in the MA category that should be rated R and that means children are playing games designed for adults."

ACCM's Professor Handsley does not think there should be a R rating in Australia, but she says something must be done to fix the current system.

"There's something wrong with the ratings system and it needs to be cleaned up," she said.

"But that's not to suggest we'll solve all the problems by making R rated games legal. That's not the answer to problem - the solution is to clean up the classification system, make sure the criteria are applied consistently across games.

"We want to see a classification game that is credible and that works well for all concerned."

Earlier this year a zombie shooter game Left 4 Dead 2 was refused classification due to its gory content. It was later given an MA15+ rating after the distributor toned down the content.

Classifications laws cannot change without the support all state and territory attorneys-general.

South Australian Attorney-General Michael Atkinson has opposed the idea, leaving many in the gaming community to see him as a "road block".

Mr Atkinson has already expressed his concern about MW2 getting an MA rating.

"I worry about any game that encourages gamers to perpetrate extreme violence and cruelty on screen, but this game allows players to be virtual terrorists and gain points by massacring civilians," he said.

"Expecting game designers to be responsible by not glorifying terrorism will always lead to disappointment."

A Classification Board spokesperson says the depiction of violence in the terrorist stage did not exceed the strong level, and in all other stages the killing of a civilian would result in immediate mission failure.

Reviewing a computer game is a matter for the Classification Review Board, which says it has not received an application to review this computer game.