command /pvp [<text>]:
    permission: *
    trigger:
        if {pvp} is not false:
            set {pvp} to false
            send "wylaczono"
        else:
            set {pvp} to true
            send "wlaczono"
on damage:
    {pvp} is true
    if attacker is player:
        if victim is player:
            cancel event