Elegance of game mechanic

Elegance = Maximum emotional and diversity player experience with minimum learning curve and developing cost.

Traits of elegance:

1. Mechanics could be elegant when they can interact with most of other mechanics.

2. Simple Mechanics could be elegant.

3. Mechanics with multi-function could be elegant.

4. Mechanics with unique roles could be elegant.

5. Mechanics based on players' behavior and habit could be elegant.

6. Mechanics with high frequency and repetitiveness could be elegant.

7. Mechanics which don't result in in-game hidden limit could be elegant.

8. Mechanics based on existing UI could be elegant.

From: https://www.amazon.com/Designing-Games-Guide-Engineering-Experiences/dp/1449337937