Few people will object to the fact that the three trends leading the crypto market in 2021 are De-fi, games, and NFT. Ethereum, which has led such trending possible by providing smart contracts, is at the center of change. However, due to soaring gas costs to process Ethereum transactions, other mainnet, or Binance Smart Chain supporting smart contracts, Solana, Cardano, Polka Dot, Terra, Avalanche, Clayton, Flow, and sidechain or Layer 2 chains such as Polygon, Abitroom, Optimism are also growing rapidly around De-fi, Game, and NFT. It can be said that it is an explosive expansion of smart contracts. What we should pay attention to here is that each of these three areas started as independent areas, but began to be closely related to each other in the process of growth. ETH price changes Game-based NFT and De-fi The direct Intersection in three areas is a crypto-based game. Even if a publisher that provides a game server fails, characters and items needed for the game as NFT wil...