Call of Duty creator Infinity Ward says Black Ops developer Treyarch did things to the series that it would "never do", such as the cult Zombies multiplayer mode.
Speaking at a Modern Warfare 3 event yesterday, Infinity Ward creative strategist Robert Bowling said the difference of approach from the two CoD developers is good for gamers because every year they're getting "a different style".
"What Treyarch has done - and what I actually think is fantastic where we are now - is they've really taken Call of Duty in a different direction. No longer are you getting the same game every year, but you're getting a different style of the same core Call of Duty design," he told GamerZines.
"Every developer has their own personality and their own direction, and more so than ever we're seeing people who really enjoy this style and the other. And it's not a black and white good and bad; they're very different experiences but in the same core gameplay.
Bowling added that he believes Treyarch's alternate approach has "turned out fantastic".
"Rather than trying to cannibalise each other, they do things that we would never do but have turned out fantastic - like their Zombie modes - and added new features to multiplayer that we would never add, just because they're a different style," he said.
On Black Ops' occasionally shaky PS3 online mode, Bowling sad he didn't know if Infinity Ward's brand was at threat from mistakes made by other teams.
"I don't know. I think it's important to make sure that as a whole we listen to feedback as a brand.
"When we go into development we're making sure that we're aware of what people want to see even if it wasn't something that was in a game that we did. All I can say is that it's our responsibility to make sure that we're attending to anything.
"I know a big question early on for development on Modern Warfare 3 was 'what's the difference between 360 and PS3?' We made it very clear that it's always been an Infinity Ward standard to make sure that both platforms run equally and to make sure that they're receiving the same attention, dedication and quality."
Modern Warfare 3 looks set to smash UK pre-order records.