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When you unzip the Starter Pack, you will find two folders: "Server" and "Client". Open the "Server" folder to get your RuneScape server up and running.  Open the "run.bat" (Windows) or "run.sh" (Mac and Linux) program. Wait for the Starter Pack Panel to appear. This may take a few moments. If you receive errors, you most likely have not installed the JDK. Enter a port. Typical ports for RuneScape private servers are 43594, 43595, and 5555. Click Save & Compile. Click Run Server. Your RuneScape private server is now up and running. In order for others to connect to your server, you will need to open the port that you specified in the previous step. In order to do this, you will need access to your router's configuration page. For details on forwarding ports, check out this article.  In order to forward the port, you will need to know the internal IP address of the computer running the server. Once you have forwarded the correct port, you can connect to it from anywhere using the proper client software. If you are only planning on using the server on your private network, you do not need to forward any ports. This is only for those that want anyone to be able to connect. In order to connect to your private server, you will need to configure the custom RuneScape client. The client is the program that connects to the server and allows you to play. Each private server requires its own special client. Open the "Client" folder in the Starter Pack.  Open the "run.bat" (Windows) or "run.sh" (Mac and Linux) program in the Client folder. Enter in a name for your server in the Set Title field. In the Set Host field, enter in the IP address of your server (most likely the computer you are using right now). If you are connecting over the internet, it will need to be the public IP address. If you are connecting over a home network, then it will need to be the private IP address. In the Set Port field, enter in the port you specified when setting up the server. Click Save & Compile. As you get more familiar with running a RuneScape server, you may decide to make modifications and changes. Each time you make a change on your server, you will need to recompile it. To do this with the Starter Pack, run the "Comile.bat" program in the Server folder whenever a change has been made.  Simply running a copied version of another RuneScape private server will not gain you many players. Players like to play on unique servers, so if they come across a copied or "leeched" server, they will most likely skip it and not play. To make your server stand out, you will need to make a lot of changes to the base game. If you want to get serious about making changes to your server, you will need to learn some basic Java. This is the language that RuneScape is built in, and making any changes to the server requires coding those changes in Java. There are a large number of tutorials and community forums that can help you gets started writing custom RuneScape code.
Compile your server. Forward your ports. Configure your client. Make changes to your server.