Griefing

From The Urban Dead Wiki

A catch-all term for intentionally annoying and disruptive behavior that is technically legal under the rules of a game. Being annoying isn't griefing in itself, but doing something simply to spoil other players' enjoyment is. Hindering other players' gameplay can be seen as griefing, depending on the context.

A human player who continually knocks down barricades or builds them so others can't enter buildings, or a zombie who only attacks other zombies, might be considered a griefer. This is sometimes a matter of perspective, but if an action hurts other players without benefiting the person in question, it could be considered griefing. Continually killing a specific player, over and over, is also considered griefing.

Before the recent change, some players considered the skill headshot to be a form of griefing because it removed XP from zombies without benefit for the shooter beyond the normal benefit for the kill (Damage Caused + 10 XP). See the headshot page for the history of the skill, including initial reasons for implementation.

Some don't believe there is such a thing as griefing because the actions can be explained from an in-character standpoint. More on this can be found on the Does griefing exist page.