> For the complete documentation index, see [llms.txt](https://realgo.gitbook.io/whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://realgo.gitbook.io/whitepaper/beginners-guide/tutorial-21-pet-release-system-how-to-release-pets-to-earn-upgrade-materials.md).
# 【Tutorial 21】#Pet Release System# How to Release Pets to Earn Upgrade Materials
The **Pet Release System** allows players to set their captured pets free in exchange for valuable in-game resources. When a pet is released, the player will receive a certain amount of **Fragments**, which are essential materials used for **Pet Star-Up** (upgrading a pet’s star level).
**How It Works**
1. Players can select any pet they no longer need and choose the **“Set them free”** option.
2. Once confirmed, the pet will be permanently removed from the player’s inventory.
3. In return, players receive **Fragments** based on the pet’s rarity and level.
**Fragment Utility**
* **Star-Up Material:** Fragments are used to upgrade the star level of other pets, improving their attributes and overall battle power.
* **Progression Resource:** The Pet Release System ensures a sustainable in-game economy, encouraging players to capture, upgrade, and optimize their pet lineup.
**Key Notes**
* Released pets cannot be restored.
* Higher rarity pets yield higher rarity **Fragments**.
* Strategic release of surplus pets helps players grow stronger more efficiently.
**SSR** and **SR** pets **cannot be released**. **S**, **A**, and **B** grade pets can be released to obtain a **Star-Up Material** corresponding to their Rarity.
**Pet Release Material Table:**
**Star Wings:** This item can only be obtained from **event drops** and **cannot be acquired through pet release**.
