Ideas for Stendhal/PvP Challenges
Player vs. Player Combat - Current Situation
Currently players can attack each other except in situations where the players' strenght differs too much. In those situations the weaker player can attack the stronger one to start a battle. Some players use PvP combat to increase their ATK and DEF stats quite extensive.
In some situations the Status Quo causes trouble, e.g. player B tricks the weaker player A into attacking him and kills him in PvP combat.
Player vs. Player Combat - Possible Options
Although training/camping is not that important anymore players still want to train (and do so), thus simply deactivating PvP combat might cause a lot of complaints.
Implementing some kind of Opt-Out for PvP could be easily abused.