The Five Layers of Player Satisfaction (excerpt)

Each of these different layers builds upon the part that comes before it. If a mechanic doesn’t feel good, then mastery is going to be painful. If there is no purpose, then mastering it is unrewarding. If the purpose of two mechanics overlaps or the purpose is unclear, then you can’t make a meaningful choice. (full article via Flark Design)

  1. Implementation
    No matter how interesting, well thought out, or balanced your mechanic is, if it doesn’t function, then you can’t expect someone to use it. 
  2. Feel
    The feel of a mechanic is all about your reaction the first time you use it. (ex. the way your bass kicks when you fire that shotgun) if it doesn’t feel good then you won’t stick around to master it.
  3. Mastery
    Mastery is responsible for that rush of excitement when you use a mechanic effectively, and the harder it is to master the more satisfaction you feel. It is impossible to realize fully and attracts precisely because mastery eludes. (ex. addicts of World of Warcraft)
  4. Purpose
    A strong purpose not only helps you to get over the initial “steepness” of the Mastery curve, but also provides extra satisfaction in using it effectively. It is the designer’s job to make sure that a mechanic has a distinct purpose, but more than this he must also make sure that the purpose is clearly defined to the player. “Human beings are purpose maximizers.” If you want player satisfaction you need to not only strive to create a purpose to your mechanics, but also to the game as a whole.
  5. Meaningful Choice
    Choice is what separates games from other mediums, and it the meaning behind your choices that make games so much fun. Too often games try and give the player too MUCH choice. The more choice you give a player the harder it actually is for them to make a meaningful choice because they can no longer accurately judge the value of one choice against another. This is sometimes referred to as the “Paradox of Choice”, and it is something that you always have to keep in mind.