While there is little question that Grand Theft Auto V will hold the title of biggest seller for 2013, that’s not to say that there will be no competition. Call of Duty has been a super-reliable franchise for Activision Blizzard, Inc. (NASDAQ:ATVI). Each of the last four annual releases have surpassed $1 billion in sales, each with more than 20 million copies sold.

Call of Duty Ghosts

Call of Duty: Ghosts storyline

Out Tuesday for PlayStation 3, Xbox 360, Wii U and PCs ($60, ages 17-up), the game will see a major overhaul of its storyline with help from Oscar-winning screenwriter Stephen Gaghan, who wrote Traffic.

The game will take on a family aspect in this latest iteration entitled Call of Duty: Ghosts. The game is set in the post-apocalyptic near-future following an alien attack on the United States. The game, as per usual, will have a globe-trotting storyline with a number of twists. The main characters in the single player mode will involve two brothers, Hesh and Logan, serving under their father and will be joined by their family dog. Not a dog that needs looking after, rather a battle-hardened Special Forces trained German Shepard named Riley.

Improved character customization

Call of Duty has always had a ridiculously popular online multiplayer game mode, and this year’s release will feature an improved character customization scheme with 20,000 combinations including the inclusion of female soldiers for the first time. Call of Duty has seen a growth in online play from females and is embracing this. In the new “squads” mode you can join others to fight computer-controlled opponents. In its new “Extinction” mode, four players will need to work together to fight off an alien invasion.

Publisher Activision Blizzard, Inc. (NASDAQ:ATVI) and main development studio Infinity Ward made the right move shaking things up a bit, says analyst P.J. McNealy of Digital World Research. “You always have to take risks to avoid franchise fatigue, and new stories are needed,” he says.

GTA V vs. Call of Duty: Ghosts

While GTA V will outsell Ghosts this is not necessarily a bad thing. “This franchise has been the biggest and best franchise in this console cycle,” McNealy says. “The huge sell-in numbers for (GTA) bodes well for [Ghosts] coming in north of 25 million units.”

Wedbush Security analyst Michael Pachter believes that sales could be down as much as 10% as consumers will feel the effects of having just purchased a new PlayStation 4 or Xbox One.

Ghosts will be made available on the PlayStation 4, out Nov. 15, and the Xbox One, Nov. 22.