If RuneScape is being blocked by your firewall, you would be unable to connect to our servers - often preventing login or stopping you from connecting successfully to a world.
You can set up exceptions in your computer and router's firewall to allow successful access.
If you have firewall and antivirus software installed on your computer, make sure you have added exceptions for;
For instructions on how to do this check your firewall software's website.
On your router, you would need to open the following ports;
443, 43594 and 43595
This will vary depending on your make and model of router, and instruction booklets are often included with your router or can be found on the manufacturer's website. You can also find information on How to Forward a Port here.
Check out more information and solutions to Common Connection Problems.