Master Chief could have been in your Gears of War 3, killing your Locusts, had Microsoft not been too "squeamish" and just given Cliff Bleszinski the go-ahead to include the faceless green warrior in the war for survival against the Locusts.
In response to a question from Complex regarding crossovers from other Xbox 360 games possibly invading the Gears universe via DLC, Gears lead designer Bleszinski revealed that he had already considered the option.
"I'll let you in on a secret," he said. "I actually approached Microsoft on getting Master Chief into the game, but those guys are kind of squeamish."
"One of Halo's successes is that it's a soft M [rating]. Gears pushes it further. I'm creatively comfortable with that, though it can limit what you do. If you had to break it down, I'd say that Gears is like Mortal Kombat and Halo is like Street Fighter," he jokingly explained.
"But if we were to get Master Chief, we'd get his model, put him in a COG suit, make it blow up, and do some test animation work," he added.
"We'd have to see what his head looks like being blown to smithereens or how his arm would look getting sawed off. Then we'd package up the test footage, put it on YouTube, and let the fans get a kick out of it because everything is meta these days.
"That's why Gears is packed with Easter eggs. That's the kind of metagame we have to think about in a post-Red Dead Redemption world."
The Gears of War 3 beta is currently underway, with Emergence Day set for September 20 this year.