> For the complete documentation index, see [llms.txt](https://castleoverlord.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://castleoverlord.gitbook.io/whitepaper/about-the-game/why-play-castle-overlord.md).

# Why Play Castle Overlord?

* **Low Entry Barrier**. Anyone can play the game for free with limited features. Players can unlock the full game and earn rewards by owning at least one NFT trooper. 
* **Unlimited NFT Variations.** Each minting period offers a huge variation of new NFTs created by our talented artist. Every NFT unit is a combination of randomly selected parts that have their own color and design. These parts also come in different rarities that affect their appearances and in-game stats. The virtually unlimited combination ensures that every NFT is unique, and the limited minting period keeps the value maintained by scarcity.
* **AFK-Friendly.** Players have the opportunity to gain resources both actively (assault battles) and passively (defense battles).
* **NFT Added Value.** The value of an NFT in Castle Overlord is not only determined by its looks. Since every NFT is a playable unit, their battle capabilities are also part of the equation. By upgrading an NFT, it will increase in strength and become more desirable in the market.