In ye ancient days of yore, Jared Sorensen (designer of many things) put forward three questions that now collectively bear his name. Between writing on the subject, I've been attempting to decide how I wanted to answer.
What is your game about?
Sword & Scoundrel has the tag: A game about Passion, Violence, and General Skullduggery. Above all, the game is a passion play. It's medieval morality theater presented as an HBO or AMC-style character drama. Players decide what's most important to their character, what they care about, what they want, the lines they will not cross. Through play, we challenge them to see how far they are willing to go and what they are willing to sacrifice. The game is about moral conflict, with forces set in motion against the player's goals and beliefs. Finally, it's a blood-opera with the player's passions leading to quick and brutal violence. We wanted the fantasy equivalent of a western or a john woo film, with swordplay being quick, flashy, and lethal.
How does your game do this?
Mechanically speaking, characters are not just their attributes and skills. Their goals and beliefs are represented by player-nominated phrases called Drives which have a mechanical weight to them. Similarly, characters have Traits which can represent everything from the character's history and background to their physical or personality quirks and their relationships with other characters, including the players in their group. These all have mechanical significance in play, often giving them additional dice for their pool when relevant.
On the other side of the coin, the game is written in such a way that it is explicitly about conflict. If there is nothing in conflict and nothing at stake, there is no roll made. Further, while the game goes out of its way to play up its blood-opera persona with a detailed combat system, the rules support conflict in a broad range of arenas. The current beta supports anything when rolled as a simple conflict, but as we get the opportunity we intend to add a fully formed social combat system, faction rules, magic, and other forms of more abstract conflicts.
How does your game encourage/reward this?
The primary reward mechanism is through the accumulation of Drive Points. When players engage in conflicts with their drives, they are rewarded for it through additional dice that drive is worth. These dice come up as bonus dice in any conflict that is directly about the drive in question. Further, when players engage in certain behaviors that highlight their drives and traits, they can gain additional points that can be added to the drive of their choosing. The quickest way to earn these points is often to allow your drives or traits to get you in trouble, rewarding the player directly for making choices that are in line with who their character is even if those choices are not the optimal way to get what the player might want. Finally, these drive points can be spent to increase any of the character's abilities or traits or learn new of the same.
In short, players advance solely by making the kinds of characters suitable for good character dramas (ambitious, resolute, yet flawed) and then role-playing them in the fashion that these characters tend to behave (struggling between who they are and what they want). When they do this, the game not only gives them more dice to throw around in the conflicts they will face but also gives them the means to improve their character's scores as they play.