Produced by LDN Noise, "Lotto" is described as "hip-hop" song enhanced by the heavy Auto-Tune with the lyrics about a man feeling so lucky, like he won the lottery after meeting the girl he loves.

Apart from Exo performing the song's high-powered choreography, it also shows scenes of the members gambling, watching cockfights, burning piles of money, and other risk-driven activities, before they and a female co-star are taken down by a S.W.A.T.

Member Kai was absent from promotional activities due to an injury he sustained during the concert tour.

[7] "Lotto" was deemed "unfit for broadcast" by KBS, MBC and Mnet, thus was promoted with modified lyrics under the alternative title "Louder" on these TV channels.

[10] The song went on to win first place seven times in total on South Korean weekly music television shows.