[In this in-depth article, originally printed in Game Developer magazine, designer Boutros takes a close look at difficulty in games, asking how creators can add unique, high-end challenges which excite, but don't frustrate skilled players.]

Difficulty modes in games are rarely discussed as an important factor in our business. In some games, they are well-thought out additions, built for the hardcore players. In other games, these modes are an afterthought, provided to appease a publisher, or as an attempt to provide direction to multiple audiences attracted by the same product.

For almost all developers though, difficulty modes are tackled at the end of the project when the game is being tuned, and they are tough to implement well without significant time and thought.

For this piece, I'll aim to explore some methods and philosophies behind how difficult play has been successfully implemented in games overall, either in terms of general difficulty, or within an optional objective that recontextualises play (such as Rare's super-tough multiplayer bonus unlockable objective in GoldenEye for the Nintendo 64).

We'll explore where certain methods have worked, failed, and where they are simply not relevant anymore. Since difficulty is so subjective, I'll focus arguments around the following ideas:

"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."

Choosing a high difficulty is the act of wanting to be tested on the part of the player. The reward of passing a test is a feeling of worth and accomplishment-and to make a test enjoyable is to make it challenging, while also achievable. Tuning difficulty in a quick and dirty way can also change the game's play fundamentally-this is something many developers don't factor into their decisions enough.

Tuning for Tough

Many games have sought to copy Rare's N64 GoldenEye model for greater difficulty - double damage from enemies = harder game - but within the context of other factors, doing this can actually change the consistent play type of the game, and thus change the experience in a fundamental and arguably unsatisfying way.

Let's say there's a fictitious FPS called NaziShoot 2000. In this game's normal difficulty mode, the player can usually get shot, have a second to think, recover, then react. In tough mode, players cannot risk being shot as the increased damage and AI kills them almost instantly.

This forces players to move and act more conservatively. In an ideal-world's well-designed tough game, it would be possible to play through and not die, if the player used the utmost care and thoughtfulness. However, this game had to hit a deadline so the tough mode had to be evolved from the normal mode, and tuned to a formula. In this memorizing bottleneck scenario, surprise snipes to the head, and learning from trial and error become the dominant way to play.

And there is the difference: whereas one mode is a reactionary and lightly memory-reliant experience, in the tough mode, 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.

This is a classic tenet of the old school 2D arcade shooters. In a 3D game where an additional axis dramatically adds to your things-to-worry-about radar, control complexity is usually increased, and gameplay acts-core gameplay sequences such a shooting something and then grabbing a power-up-are spread across a longer timeline because of the physical world's scale increase. If the player can be killed in one hit, or by other fatal game features, this can often result in an intense feeling of frustration, and quite possibly lead to dissatisfaction with the game overall.