The moment when a game really comes to life and triggers player's real emotions is when all the mechanics work together to create experiences. Usually, these interactions are called dynamics, such as in the case of the aforementioned MDA Framework.
The most striking difference between a mechanic and a dynamic is that a game designer has full control of the former but much less of the latter. It is only in the hands of players that dynamics can emerge from mechanics and it is the game designer's job to make sure this happens in the way they envisioned.
Having less control doesn't mean that designing the mechanics and just hoping that they'll work will be enough. The fun of video games ...
