Lux are light particles which appear in Kingdom Hearts χ and Kingdom Hearts Unchained χ. They are gained by defeating Heartless and are used to rank the players on weekly basis resulting in more and rarer prices the more the player collects. The Lux determines all regular rankings in the game. All Lux collected during the week by the Player sets his or her individual rank while the amount gathered by the whole Union sets the Union's place in return.
Kingdom Hearts χ
There are several factors that can influence the amount of the collected Lux. very assist card the player uses increases the drop rate of Lux by a small amount; this depends upon the used assist card's level. A number of times a day "Lux Up Time" occurs lasting one hour and automatically doubles the Lux earned in this time. The team that collects the most Lux during the day wins the daily team battle.
Kingdom Hearts Unchained χ
Like in Kingdom Hearts χ, there are several factors that influence how much lux can be obtained. Having a medal with a skill like Lux Plus can, if activated, result in increased lux. Certain events also have "Bonus Times" which can double the amount of lux gathered during a mission.