Game designer Daniel Boutros looks at how to give games a challenging difficulty without frustrating the player in a feature on Gamasutra. The article, originally published in Game Developer magazine, establishes two tenants for how effective levels of difficulty.

• A player must always feel like the failure of a challenge is entirely his own responsibility, and not a fault of a poorly designed product.
• “The player must understand how and why he failed, so that he can learn from his mistake and increase the feeling of failure being his responsibility.

Boutros traces the traditional method for increasing difficulty to Rare’s shooter GoldenEye, where higher difficulty levels simply meant enemies do more damage. “In the tough mode,” says Boutros, “the game becomes very classically rooted in trial and error, using memory play as the core consistent play type. The only way a player can survive with meager resources and a damage disadvantage is by trying, dying, remembering, and restarting.”

In other words, play through and die until you’ve figured out where every sniper is, know which doors hide enemy ambushers, and know exactly where to point your rifle to take them all out. That’s not fun, and it does not create an immersive experience.

Increasing enemy damage or numbers, charging AI aggression, implementing a time limit, and restricting player resources like ammo or health are the simplest ways to increase difficulty, but the easiest solution is never the best. Rather than simply doubling enemy damage, Boutros argues that developers need to integrate these techniques thoughtfully and budget time for testing and fine-tuning them.

Boutros highlights games like Ikaruga, Halo and Call of Duty 4 as having excellent grades of difficulty. Ikaruga’s higher difficulty levels made mastering that game’s white and black puzzle mechanic more essential to the player’s survival by causing enemies to send out shrapnel if destroyed by the wrong colored weapon.

The Call of Duty games puts checkpoints right before periods of intense action. This keeps the game tight, and it also prevents the frustration of running through a long stretch of cinematic story events over and over because the part after them is tough and there’s no way to save.

Bungie’s Halo series is legendary, if you’ll pardon a pun, for the hearty challenge of its Legendary difficulty settings. “It’s not like we just cranked every enemy’s health by 200% and called it Legendary,” said Halo 3’s gameplay designer Francois Boucher-Genesse in an interview with Boutros.

“There was a good amount of custom changes made per mission as well,” continued Boucher-Genesse. “What did make a difference was the time spent tweaking and fixing issues to make the game fun on every difficulty level. All titles had more bad guys, stronger and more accurate enemies with faster projectiles. And they used similar numbers for each of these parameters.”

Boutros’ analysis is far more detailed and definitely worth reading. He offers good solutions to make games challenging, not frustrating, but really recommends that developers take the time to experiment with tried-and-true modes of increasing difficulty and make them work for their title.

“When your company budgets for tuning of difficulty levels,” says Boutros, “the result is extended longevity for the game, and increased enjoyment for players at all levels.”