Imba

Imba, an abbreviation of imbalanced, is used to describe skills, equipment, or gameplay mechanics that give certain players an unfair advantage over others. Because Guild Wars has "balanced competitive play" as one of its stated design goals, calling something imba is viewed as a strong criticism.

This slang abbreviation is common among online communities of gamers. It is now common in nearly every online gaming community, not just those of online RPGs.