on damage of player:
	attacker is a player
	{pvp} is set
	cancel event
	message "&cPvPは不可能です!" to attacker
command /pvp:
	permission: operator
	trigger:
		if {pvp} is not set:
			set {pvp} to true
			message "&aPvPをonにしました"
		else:
			clear {pvp}
			message "&cPvPをonにしました"