NFT Upgrade System

Travel NFT Upgrade

When NFT reaches level 5, user can upgrade NFT Quality to a higher Quality by using 2 NFTs of the same Quality but losing 1 NFT. It retains the Attributes value of the base NFT.

Users can add The percentage of success Quality up their Travel NFTs by burning GAS

Quality	percentage of double	percentage of success
Common	20%	70%
Uncommon	15%	60%
Rare	10%	50%
Epic	5%	40%
Legendary	NA	NA