Deus Ex: Human Revolution's heavily maligned boss battles were not developed in-house at Eidos Montreal, they were instead out-sourced to minnow studio Grip Entertainment.

The boss battles are recognised for having an action focus and frustrating difficulty spikes. Grip Entertainment's Paul Kruszewski admitted crafting the encounters was a difficult task.

"Full confession: I'm a shooter guy. I was coming into this not knowing a lot about the Deus Ex world," he said.

"The guys at Eidos gave us the design, gave us the engine. We brought in our own behaviour tree engine and we gave them back that experience.

"Boss battles are special moments. There were two challenges: we had to take our tech and inject it into the DEX3 engine. And then within DEX3 itself is, you're coming at it, and you can be anybody, you can have this augmentation, that augmentation, this weapon…

"And so, balancing all this stuff, you don't know the priority of the guy is coming into the game, and you want to give him a great experience. You want to be true to the designer's vision, but you want to give the player a great experience. So balancing was brutally hard."

But Paul Kruszewski has some advice for those struggling with the boss battles.

"There is a flow to these guys. We think there is a lot of fun. You've got to figure out what their OODA loop is. You've got to get in that and it's going to work out.

"But if you panic, you're going to die. Simple as that. So just remain calm. Be Zen, and orient, observe, decide and act."

Is anyone aware of any other titles that had outsourced boss encounters?

[Thanks Eurogamer]