Geek of the week: mastery

Geek of the week: mastery is a moon badge. To acquire it, users have to complete 5 mastery challenges in 1 week. No energy points are given upon this badge.

Similar badge(s)

 * Challenge Accepted / Makes Perfect
 * High Five / Five is Alive!
 * Hang Ten / Fingers or Toes
 * Geek of the week: practice