Originally Posted by
Doc
FFA = Free for all, you can attack anyone with no restrictions (although there might be consequences), does not include anywhere
Ganking = attacking "helpless" targets, usually consists of making (large) group, roam the map for newbs/single/highly overwhelmed targets, and run away at anything that looks slightly capable of defending it/themselves - short - reward with 0 risk
Griefing = harrasment. What exactly is harrasment in certain game is decided by devs, can be verbal-"physical"(from ingame point of view), spawn killing where defending player cannot react before he is killed is classical form of griefing