New World - Temp Luck System - Psuedocode (Javascript).

newworld_templuck.js

var baseTempLuck = 50;
var maxTempLuck = 100;
var TempLuckPerLevel = 5;

var eliteTempLuckMod = 2;

Number.prototype.clamp = function(min, max) {
  return Math.min(Math.max(this, min), max);
};

if (mob.isDead())
{
	var divLuck = baseTempLuck / mob.AttackedBy.length;
	if (mob.elite)
		divLuck = divLuck * eliteTempLuckMod;
	
	for(var i; mob.AttackedBy.length; i++)
	{
		var player = mob.AtttackedBy[i];
		
		// Level diff.
		var levelDiff = mob.level - player.level;
		
		var tempLuck = (levelDiff * TempLuckPerLevel) + divLuck;

		// If less than 0 then no tempLuck added, and enforce maxTempLuck.
		tempLuck = tempLuck.clamp(0, maxTempLuck);

		if (tempLuck > player.tempLuck)
			player.tempLuck = tempLuck;
	}
}

if (chest.isOpened())
{
	var luck = player.luck + player.tempLuck;
	player.tempLuck = 0;
}