For some reason, over the past few days, I’ve returned to one of my oldest standby games: Gemcraft. The experience has me thinking once again about a particular dynamic that exists inside certain (rare) games, one that I find both deeply empowering as a player, and incredibly impressive as a developer.

[ INFORMATIONAL ASIDE: GemCraft comes in many shapes and sizes. The one I’m specifically referring to is the Steam version of GemCraft: Chasing Shadows, but there’s also the original, the sequel/prequel, the one with the labyrinth, and Chasing Shadows (the web version). That’s like 10,000 hours of tower defense for ya, right there. HAVE AT IT, PEOPLE. ]

The dynamic is something I’ll call “Challenge Modulation”, and it is incredibly hard to pull off, as a designer. But if you can do it, the player’s world opens up in ways that few other creative choices can.

Many games have deeply powerful difficulty control systems; different knobs and levers that the player can set up to determine how hard the game is. That is not what I’m talking about here, though it is great when games do that. Good examples of that can be found across the genre spectrum: games where you can determine the difficulty of bot opponents, or how long you want a match to run, or what type of challenges you want to face, etc.

But these settings are generally outside the game itself. Once the game is launched, there’s not much you can do.

Challenge Modulation is different: it is present when the player has a set of tools available to them during play to modulate the difficult of the existing experience, to suit their momentary whim.

Gemcraft has this–though, not in the menus before you load into the game. It exists in that you can determine when to level up your gems (thus delaying your own power progression), and in the fact that you can “bomb” the upcoming waves to add enemies to them, make them more powerful, and potentially gain more mana from them. Self-challenge in GemCraft has been turned into a strategy, and seamlessly integrated into the experience.

Diablo has this, too–though, again, not before you load in. In fact, most games that involve ‘pulling’ groups of enemies who are waiting for you (Dark Souls, MMOs of various kinds) have this; if you as the player can decide how many enemies you want to fight at a time as you proceed through the level, then there is a basic form of Challenge Modulation present in your experience.

In Diablo, the experience is further modulated by the player’s abilities themselves. The player has the option of simply withholding their strongest powers, in order to make the game “harder” on a moment-by-moment basis. That constant control of difficulty is Challenge Modulation.

The experience is an impressive one. Often, with games that have this feature, the right risk/reward balance can almost completely hide the fact that there is any challenge control going on at all. Players will simply feel the constant presence of pressure options that they are either taking or rejecting. That feeling of autonomy, of control over your own experience, is an exceptional sensation. One, I think, that is in the cluster of Great Experiences that games can offer you. Choosing to take on harder challenges, as a form of personal testing curiosity, is a deeply human moment, one that our species has exerted on the world throughout our existence (I believe). Games are a perfect place to practice this skill.

I don’t think I had anything to say about this concept beyond “it exists” and “it is a high-order design success when the player can modulate their own challenge in meaningful ways during play”.

Attempt this, in your designs.