When Infinity Ward talks about Call of Duty: Ghosts' new engine, the term "new" carries an implied asterisk, at least according to animation lead Zach Volker. "When we're talking about a new engine, we're talking about upgrading significant systems within in that engine - we're not talking about throwing it all away and saying we're starting from the ground up," Volker told Official PlayStation Magazine UK.

Creating a brand-new, from-scratch engine on Infinity Ward's production timeline would require "an army of 200 engineers" according to Volker, so the distinction of "new" is made by how significantly upgraded the latest version of the engine is, as compared to the last.

"We say okay, what are the things that are significant," Volker said, "that are encompassing of the engine or its visual quality? Are those being upgraded in a significant way? Alright then, I think that warrants that we've got a new engine on our hands."