# Bridge

### Multichain

CryptoKnights is a multichain game, meaning that the in-game assets can be **imported from and withdrawn to multiple blockchains**.

### RUBY as a Cross-Chain Token

For our RUBY token to exist on multiple chains, we incorporated a **special type of ERC20 contract that can be aware of its balance on other chains**, so that the total amount of RUBY on all chains it has been deployed on remains constant.

### NFT Bridging

The NFTs in CryptoKnights will first be auctioned on a single blockchain, then can be imported into the game and withdrawn onto other chains.

### The Game is a Bridge

Therefore the game serves as a bridge for all those tokens.