In Castle Defense, roles are basically divided into sponsors (castle owners) and players. The value of the castle is increased by sharing profits and coexisting with each other. Castle owners are the holders of NFT Castle who rent it out to players. The players in turn play Castle Defense with the rented castle and earn XP which can be converted to POC. The value of an NFT Castle is also increased when a player uses it to play and accumulate XP in the process. XP that is acquired is used to create and multiply in-game assets in the form of knights, wizards, weapons, participating in the PvP battles etc. The burning mechanism of PX is continuously being developed and added in order to prevent POC inflation and also to increase the fun element of the game.