A member’s reputation is a quantified representation of their trustworthiness within an online community. Reputation is determined by a reputation system, consisting of one or more algorithms combined with ratings given to and by members of the community.

Ratings are often tied to various forms of engagement with members’ posts, such as likes or upvotes/downvotes. In such cases, a member’s reputation is determined by the aggregate engagements of all their posts and replies within a community. Some communities formalize reputations in the form of badges or leaderboards, while others opt for a simple five-point score.

Because of the actual, potential, and perceived value of reputations in certain communities, members may be incentivized to attempt to game the system in order to improve their own reputation. Methods here include self-promotion, where members create multiple additional profiles for the sole purpose of engaging with their own content, or slandering, where members target other members with negative feedback in order to lower the target’s reputation relative to their own. For this reason, community managers need to be especially vigilant when introducing a reputation system into their community.