In onlinecomputer games (especially role-playing games), leeching refers to the practice of a player joining a group for the explicit purpose of gaining rewards without contributing anything to the efforts necessary to acquire those rewards. Sometimes this is allowed in an effort to powerlevel a player. Usually it is considered poor behavior to do this without permission from the group.
This is a disambiguation page; that is, one that points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix that link to point to the appropriate specific page.