[The design director of Volition/THQ's expansive open world action title Red Faction: Guerrilla talks about the transition from being scared of player freedom to truly embracing it, including several case studies of specific missions in the game and they evolved to support meaningful player interaction.]

Designers create experiences for the player. That's a loose enough definition that there's little room for debate. But how much control is implied by that short phrase "create experiences"? Does that mean micromanaging the moment to moment play? There's a school of thought that says that's what designers do, and many of us believe it. And for some types of games it is true.

Then there are open world games. Crafted from the dust of early computer role playing games -- the original open world designs -- the goal isn't to tightly control the player experience, but rather to build a world and turn the player loose in it.

Give the player the freedom to choose his or her own path. Provide meaningful options. Encourage experimentation. Carrying over the hand-holding approach of linear storytelling games doesn't work; an open world is more than just a lobby for starting linear missions.

To truly fit into the open world model, missions have to provide the same sense of freedom that the world itself provides. And to make that work takes a change of mindset. It means letting go of being a control freak and instead embracing the chaos that's inherent in open world design.

There's a certain fear here. Much like some paranoid graphics programmers thought that their worlds were crashing down when texture mapping moved to hardware, some designers feel that they're being outsourced to code-driven systems. That fear is unfounded, even in the games that go to extremes to maximize openness.

I was the design director at Volition for Red Faction: Guerrilla. If ever there was a game that struck terror into the heart of a design team, that was it. Not only was it open world, but every single wall and fence, every door, every building -- including the ceiling and structural frame -- could be damaged and completely destroyed in arbitrary ways.

A tower could fall sideways onto a two story building, tearing through the roof and drilling straight down to the ground floor. A vehicle could explode on a bridge, making the bridge unusable for other traffic. Rubble from a building could fall in the road, preventing reinforcement personnel carriers from getting where they needed to go.

And none of this was perfectly predictable, being at the mercy of dozens variables going through the destruction engine. That tower could have just sheared off the outside wall, depending on the exact forces that caused it to topple. That vehicle could have exploded off to the side of the bridge, still creating a large hole, but one that can be navigated around. That rubble might have blocked doorways instead of the road, or even killed your attackers.

How can you even begin to control the player when all bets are off, when the traditional ploys of locking a door or blocking an alternate path with a chain-link fence don't work?

But that's the extreme case. Before considering that, let's go back to the first problem: How to build an open world mission that emphasizes player freedom?