> For the complete documentation index, see [llms.txt](https://distrup7ed.gitbook.io/bob-chain/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://distrup7ed.gitbook.io/bob-chain/game-interactions/open-upgrade.md).

# Open/Upgrade 

## Angel

Angel is a character that can be found in the main village. This character can open crystals and upgrade heroes. Angel is also avaiable on the website!

## Open Crystals

To open crystals, simply choose the desired amount and click on "Open Crystals"; opening crystals is free!

<mark style="color:red;">**IMPORTANT:**</mark> Players can only find lvl 1 to lvl 6 heroes from crystals, lvl 7 and 8 heroes can only be obtained through upgrades

<figure><img src="https://1747257664-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fyv63dOL1D6uQ8oefN7D2%2Fuploads%2F4FnZXTK13CszkkZWkcfm%2Fopen.png?alt=media&amp;token=85e6bfc4-c2e8-428f-bcfb-69d0556b3447" alt=""><figcaption></figcaption></figure>

## Upgrade Heroes

<mark style="color:red;">**IMPORTANT**</mark>: Heroes can be lost forever during an upgrade, so make sure to understand this section well before proceeding!&#x20;

Each hero has a different upgrade cost, which increases progressively based on its level.

* After opening a dialogue with Angel by clicking on "Upgrade Heroes," players can select the hero they wish to upgrade.

* A green question mark will appear instead of the hero, prompting users to reveal the result of the operation.

<figure><img src="https://1747257664-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fyv63dOL1D6uQ8oefN7D2%2Fuploads%2FbMDB2FoCIJ3KzBpZa7rg%2Fuogrades.png?alt=media&amp;token=1eb2105b-91e8-461e-824a-23be63284be5" alt=""><figcaption><p>Example of the two results: Success and Fail</p></figcaption></figure>

After a successful upgrade, the hero will increase its level by 1, along with the amount of ETH it can earn.

<mark style="color:red;">**IMPORTANT**</mark>**: Do I always lose my heroes when upgrades fail?**

No, if the player has a G-Crystal, they can decide to use it on a specific hero. That hero will be safe and will NOT be destroyed in case of a failed upgrade but will simply stay at its current level.

Players can find G-Crystals in arenas or buy them from other players in the marketplace.