> For the complete documentation index, see [llms.txt](https://docs.spellsofgenesis.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.spellsofgenesis.com/spells-of-genesis/cards/cards-upgrading-and-evolving.md).

# Cards Upgrading & Evolving

<figure><img src="/files/NrfBHxHyAt3dHyk9uE98" alt="" width="335"><figcaption><p>Card Upgrading and Evolving by Fusion</p></figcaption></figure>

1. Upgrading: Crystals, one of the in-game currency, can level up your cards to increase their power. Card rarity determines the number of levels: common (3 levels), rare (4 levels), epic (5 levels) and legendary (6 levels). Upgrading costs more as the level of a card increases.

2. Fusing: When you have two fully upgraded identical cards, you can fuse them to create a silver card (double-fused card). This one can be further upgraded with crystals. You can then repeat the process, using two fully upgraded silver cards to create a gold card (quad-fused card).

In both ways, card evolution results in increased attack power, greater endurance, enhanced spell potency (single-target spells can turn to multi-target spells), while the speed stat remains unchanged.
