on damage of player:
    attacker is player:
        if {server.pvp} is not set:
            cancel event

command /pvp:
    permission: server.admin
    permission message: Unknown command. Type "/help" for help.
    trigger:
        if {server.pvp} is not set:
            set {server.pvp} to true
            send "&6[PVP] &rPVPを&a有効化&rしました。"
            stop
        else:
            delete {server.pvp}
            send "&6[PVP] &rPVPを&c無効化&rしました。"
            stop