Here’s another way to say what I tried to say yesterday.
Play is about confronting a challenge
The basic play of D&D (and a lot of other RPGs) is that you have characters that are presented with a challenge. But what is key is that this is also a challenge of a sort for the players. They have investment in seeing their characters succeed, so playing the game well and having your characters succeed go hand-in-hand. There’s room for a Pyrrhic victory, and failure can be fun, too, but the basic idea is to confront the challenge. This also means that the challenge often extends beyond the game world, through the rules, to the players–especially as games get more complex, part of that challenge can become using the rules to greatest effect. IOW, character capabilities are the core of this, and building a powerful character is as much a part of the game as what you do with that character in play.
Play is about exploring a theme
Now, in contrast, Fiasco (and a lot of other RPGs) is all about a theme–in this case, “powerful ambition & poor impulse control”. Most of these games are built around relationships and personality traits. In order to embody a theme, a lot of them specifically start the game with untenable situations, guaranteed to change and evolve. The rules are all about that theme and those relationships and personality traits, often dictating how they change in response to happenings in the game. The players are invested in making the story meaningful, and this doesn’t necessarily correlate with their characters succeeding. In fact, a good chunk of the category–Fiasco, Sorcerer, My Life With Master, and others–are pretty much about your characters failing, and seeing exactly when and how they fail.
Play is about telling a story
In Four Colors al Fresco, the central point is to tell an interesting story–for whatever value of “interesting” the participants want. That could be deep and meaningful exploration of a theme–or it could be your typically-cliched Golden Age superhero story. The rules make no judgement as to what constitutes an interesting story, and are equally facile at creating whatever sort of story you want. What it does do is provide rules that get out of your way to let you tell that story. And since the rules aren’t focused on the challenge, you don’t have to worry about your game being derailed by bad dice luck–if the dice hate you, the worst that will happen is you’ll do your best to avoid the dice.
…But the pieces are all the same
Now, on the surface, all three of these tend to look sorta the same. Those challenges in D&D could also be seen as untenable situations. And lots of those theme-focused games produce really awesome stories, so you might end up creating roughly the same thing, given the choice. Most RPGs have characters played individually by the players, and those characters are described with a mix of characterization and capabilities. Most RPGs have something mechanical that introduces some uncertainty–usually a randomizer.
So it can be hard, looking at the mechanics of an RPG, to tell what is the core of the game. It’s often a difference of degree as much as of kind. It’s only once you peel away the layers to see which parts are mechanisms and which are the core engine that is the reason for everything else in the game that you can tell which sort of game it is.
If you don’t do that sometimes-difficult task, it’s easy to just assume a new game has the same core as old games you’re already familiar with. If you’ve ever gone to a good comedy film when you were expecting a serious drama (or vice versa), you know how the wrong expectations can ruin what would otherwise be a good experience. Which is why it’s important to understand that not all RPGs play the same, even if all the bits look familiar.