Engines are the core of every game. Unreal, Quake, and Frostbite are just three of the most well-known. With a version of the Quake engine being the basis for Call of Duty titles going back literal decades, what engine does MW3 2023 use?
CoD Modern Warfare 2023 Engine Detailed
In simple terms, the MW3 engine is called IW 9.0. It’s a more advanced version of the IW 8.0 engine built by Infinity Ward for Modern Warfare (2019). Infinity Ward used a version of id Tech 3, a type of Quake engine, to create the original IW engine. That goes all the way back in the CoD 2 days. Almost every Call of Duty game that followed used some version of the code from IW 1.0.
You can technically say that Modern Warfare 3 uses a heavily modified version of the Quake engine. However, that would be incredibly reductive. There have been so many changes made in the past 20+ years there likely isn’t too much original id Tech code left.
You can probably find some if you really go looking, especially in the physics and map design tools. I actually played a few rounds of Zombies with a developer at Treyarch back during Black Ops 2. The map design tools were the same ones all the Call of Duty studios had used from the start.
How Has the CoD MW3 Engine Changed?
That doesn’t mean things haven’t changed since then. I can almost guarantee that IW 9.0 is a vastly different beast than any of the earlier CoD engines. However, unless developers went out of their way to intentionally remove every trace of Quake code from IW 9.0, you can probably find some if you know what to look for.
I would wager — though I wouldn’t say for certain — that the easiest place to see legacy code in MW3 would be in the movement mechanics. Movement tech like slide canceling certainly wasn’t present in classic Call of Duty games. However, strafing, strafe jumping, and other advanced movement tech was present for those who understood the game at a more technical level.