RuneScape

RuneScape is a free-to-play cross-platform medieval-fantasy massively multiplayer online role playing (MMORPG) game developed by Jagex. RuneScape is currently the worlds largest free to play MMORPG game with over 200 million game accounts. RuneScape is a browser-based game and can be run on Windows, Mac OS X and Linux using any popular web browser.

RuneScape is set in the medieval-fantasy world of Gielinor, where your character can explore the vast realm, completing various challenging quests, killing monsters, engaging in epic battles in PvP mode and much more. 

"The world of Gielinor is truly enormous, with a mass of different cities, races, clans and dungeons to explore. Whether it’s practicing in the friendly, accommodating land of Lumbridge, discovering unsavoury characters in the rough-and-tumble docks of Port Sarim, or slaying other players and bloodthirsty monsters in the barren lands of the Wilderness, there’s a huge variety of things for players old and new to explore every single day."

Some features include:

• Classless system - your character is not restricted to a specific class (eg. Warrior or Mage) letting you customise your character the way you like.
• Gain experience points to level your character
• Hundreds of epic quests to complete, thousands of monsters to battle and many skills to master
• Player vs Player (PVP) and Player vs Environment (PVE) Combat
• Play straight from browser - no download required

System Requirements

1 GHz processor or faster
512 MB RAM
128 MB OpenGL or Direct X compatible graphics card
Windows, Mac OS X or Linux
Latest web browser with Adobe Flash Player installed
Java Runtime Environment 1.6 or newer
Internet connection

Download the game client here (Windows and Mac OS X only)
Play for free at runescape.com