With regard to the contemporary discussion of gamifying processes in various domains, it is obvious that there exists a naive notion that simply adding leaderboards/pins/points/badges would lead to success. Even though other instances of gamification mechanics could actually perform better. The literature has not yet managed to prove whether different domains require different mechanics in order to impact on engagement and motivation. To address these critical issues, a literature review was conducted across six domains that examined game mechanics, including their uniqueness for gamification research. Findings show a myriad of mechanics with different sharing properties, which are more or less domain-congruent. These mechanics can be separated into four levels: general, mostly similar, partly similar and unique. The findings enable a better understanding of how to employ situation-congruent mechanics to a given context, which is important for both research and practice.