Fallout co-creator Tim Cain recently shared his thoughts on the fundamental principles of non-linear design in a new video. In his latest upload, titled "Eight Level Design Guidelines," Cain explores the tension between a developer's intentions and how players actually interact with a game world.

Avoiding Assumptions in Non-Linear Design

Cain’s primary rule for level designers is simple: never assume a player will follow a specific path or engage in a predetermined sequence of events. "Rule one, our game is non-linear—don't assume that players will go somewhere first or talk to someone first," Cain explains.

He specifically highlights the issue with NPC guards as a way to illustrate why non-linear design fails when developers are too rigid. He warns against placing a guard outside a town and expecting every player to stop and engage in dialogue.

The Pitfalls of Forced Interaction

Cain expressed a particular distaste for mechanics that force interaction, suggesting that developers often use "bad practice" to steer players. His concerns include:

  • Placing gates that only open after a specific conversation occurs.

  • Forcing an NPC guard to initiate a conversation with the player.

According to Cain, if a player is capable of shooting that guard from a long distance and killing them, they will simply enter the town without ever talking to them. While a developer might think it is acceptable because "everyone in the town will attack you," Cain argues that theer job is to provide a map for players to play on, not to make assumptions about their order of operations.

Designing with Purpose and Freedom

Cain believes that effective design requires developers to understand the core purpose behind every mechanic they implement. He has previously expressed "ineffable sadness" when reviewing design documents that rely on locking players in rooms until certain tasks are completed.

He argues that such restrictive methods demonstrate a fundamental misunderstanding of why people play games in the first place. To avoid development errors, Cain suggests developers must maintain a clear vision for their work:

"If at this point you don't know what all of this is in service of, you're going to run into problems," says Cain. "You should know why. Why am I doing all this? Why did I make this setting and tell this story with these mechanics? Once you've listed your goals, everything should fall from that."

This philosophy of freedom has deep roots in his early experiences with tabletop gaming. Cain recently noted how Dungeons & Dragons—a game he began playing in 1979 after being taught by an admiral and his officers—has heavily informed his approach to creating expansive, player-driven worlds.