Call of Duty casts players in modern combat

The sniper crouches down in the tall grass, then pauses using his scope to draw a bead on an enemy soldier, who staggers back in a spray of blood.

It is easy to mistake the scene for footage from a war movie but it is actually from Call of Duty 4: Modern Combat, a new video game that is storming its way onto the wish-lists of many armchair soldiers this holiday season.

Call of Duty 4 casts players in the role of various elite warriors such as U.S. Marines or British SAS in missions that jump around the world and even in time.

It's a departure for the series which has produced three popular World War Two-era games.

Expectations are high in part because the game was made by Infinity Ward, a highly regarded studio that was founded by the folks behind Medal of Honor, widely held to be the seminal World War Two shooting game.

We're all huge fans of World War Two and there are still a lot of stories to be told in a World War Two setting but I think we really need to prove to the public that 'Call of Duty' is not just a World War Two franchise. It's a war-based shooter and there are wars at all times, Infinity Ward founder Grant Collier said in an interview.

There were a lot of doubters when we first announced the game ... none of those people have those concerns any more.

The simExchange, an online prediction market for video game sales, expects Call of Duty 4 to sell 1.3 million copies this November and December just for Microsoft's Xbox 360, with total sales for all versions to eventually top 6.5 million copies.

It's all adding up to another breakout hit for Infinity Ward parent Activision, which has been on a roll this year thanks to games like Guitar Hero 2.

The game stands to benefit from stumbling by competitors. When Take-Two delayed its sure-fire blockbuster Grand Theft Auto IV from its planned October release date to next year, analysts immediately pointed to Call of Duty 4 as the biggest beneficiary.

The game aims to be THE military action title of its time, supplanting popular but aging shooter staples such as EA's Battlefield 2 and Ubisoft's Rainbow 6.

Is there a threat from any other game this holiday season that could hurt 'Call of Duty' sales? No. 'Call of Duty' is the threat to other games' sales, said simExchange analyst Jesse Divnich.

There is some grumbling among fans that the single-player campaign can run as short as four or five hours on the easiest settings, but where the game is really expected to shine is in its online multiplayer.

Players will be kept busy teasing out the intricacies of an in-depth weapons upgrade system and menu of perks that bestow special abilities such as moving silently or bullets that pack extra punching power.

As with most military games, realism was a priority.

Graphically, the goal was to be most photo-realistic game ever made. We created the first next-gen title ever with 'Call of Duty 2'. That was back when all these art techniques were in their infancy. With 'Call of Duty 2' under their belt, these guys have really mastered them, Collier said.

Developers visited military bases and tagged along for live-fire exercises, and the very people the game portrays are some of the game's biggest fans.

Talking to World War Two vets, the ones that are still around, they don't play video games and don't really care. But these guys are hot to trot for video games, Collier said of the Marines.

Call of Duty 4 was released on November 6 for the Xbox 360, Sony PlayStation 3 and Windows-based computers.