# NFT Upgrade System

### <mark style="color:blue;">Travel NFT</mark> <mark style="color:blue;"></mark><mark style="color:blue;">**U**</mark><mark style="color:blue;">pgrade</mark>

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**

<table><thead><tr><th width="190.33333333333326">Quality</th><th>percentage of double</th><th>percentage of success</th></tr></thead><tbody><tr><td><strong>Common</strong></td><td>20%</td><td>70%</td></tr><tr><td><strong>Uncommon</strong></td><td>15%</td><td>60%</td></tr><tr><td><strong>Rare</strong></td><td>10%</td><td>50%</td></tr><tr><td><strong>Epic</strong></td><td>5%</td><td>40%</td></tr><tr><td><strong>Legendary</strong></td><td>NA</td><td>NA</td></tr></tbody></table>