Minimum:

Requires a 64-bit processor and operating system
OS: Windows Vista or higher
Processor: Intel i3+/AMD @ 2.4+ GHz
Memory: 4 GB RAM
Graphics: GeForce 400x, Intel HD 4x, AMD Radeon 7xxx +
Network: Broadband Internet connection
Storage: 8 GB available space
Additional Notes: Internet connection required to play, offers in-game purchases. The following operating systems are no longer officially supported by RuneScape, and you may not be able to play if using them: Windows 95, 98, ME, XP

RuneScape screenshots