on damage:
    if {pvp} is false:
        cancel event
        
command /pvp [<text>]:
    permission: pvp.cmd
    usage: /pvp on/off
    trigger:
        if arg 1 is set:
            if arg 1 is "on" or "off":
                if {pvp} is false:
                    set {pvp} to true
                    stop
                if {pvp} is true:
                    set {pvp} to false
                    stop