RTP must be displayed in all gaming machines or made publicly available by all casinos, whether online or land-based. Online casinos usually publish the RTP of every slot game in the information section or can also be found online on their game developers' website. Land-based casinos can be trickier because while they sometimes display boards showing the RTP of slots, not all machines follow the same percentage that is advertised. It is a marketing ploy used to attract players.