Griefing

Griefing refers to the act of an offending player (i.e. the griefer—one who causes grief) purposely ruining other players' gaming experiences by exploiting aspects of the game in unintended ways or disrupting the community. Griefers derive enjoyment at the expense of other players.

The most obvious form of griefing is constant stalking and harassment of another player. Player killing can also be seen as a griefing activity especially if the player killer knows he or she will gain no loot yet still kills the other player. For example, players training Agility at the Wilderness Agility Course are often pestered by griefers.

Reportable griefing
All these actions are against the Code of Conduct. If reported, action may be taken against the player or players involved, such as a mute or ban.
 * Harassing, stalking, or insulting players—Rule 14
 * Scamming—Rule 2

Non-reportable griefing
Although dishonorable, these actions are considered legitimate and likely will not be addressed by Jagex Moderators.
 * Kill stealing
 * PKing repeatedly