# Guide to Castle Defense ![](https://85149839-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-McOCMix-W8i2E1D5pt3%2Fuploads%2FIwYgcKMhgzEH2oIGm7uG%2Fmain.png?alt=media\&token=c1501139-abe9-40fc-8e64-6149484b8b3a) The old school tower defense game is back, as a play-to-earn based NFT blockchain game, Castle Defense. Now defend, attack and grow your territory with your NFT Castle. Sponsors buy NFT Castles that can be used by players who contribute XP to the castle while playing the game, thereby making it stronger and increasing the value of the NFT Castle. The sponsor can also sell the upgraded castle on the NFT Castle Market and earn a profit on sales. See [www.castledefense.io](http://www.castledefense.io) for more details. You can play Castle Defense by clicking this link on any browser of your PC, tablet or your mobile ( both on Android or Apple mobile phone). It is free-to-play game. You are not required to buy NFT in order to play and earn XP in this game. [**Play browser version of NFT Castle Defense** ](https://games.pocketarena.com/castle/) You can also download NFT Castle Defense from Google Play Store. [**Download NFT Castle Defense from Google Play**](https://play.google.com/store/apps/details?id=com.pocketarena.castledefense) Not interested in games, but interested in investing in NFTs? You can own an NFT Castle and be a sponsor. To buy an NFT Castle visit our NFT Castle Marketplace below. [**NFT Castle Market**](https://games.pocketarena.com/cmarket/) {% embed url="" %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://castle-support.pocketarena.com/guide-to-castle-defense.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.