> For the complete documentation index, see [llms.txt](https://xkart-racing.gitbook.io/xkart-racing-whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xkart-racing.gitbook.io/xkart-racing-whitepaper/nft/evolution.md).

# Evolution

Zorians are gauged in levels. The highest level a Zorian can achieve is level five. Higher the level, the more yield they will receive for staking. Zorians can be evolved (leveled up) by spending some $KASH tokens. Each level comes with maximum slots, after which others cannot evolve to that level. The below table shows how many $KASH tokens need to be burnt to level up and how many slots are available for that level.

<div align="left"><img src="https://2770771616-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fo1lmkuonV3yxs0BcsJoY%2Fuploads%2FehJti8ElPVcF2V2OgLWl%2FEvolution%20Cost.png?alt=media&amp;token=3a76bd07-b022-4b53-8d2a-93d40927348a" alt=""></div>