RuneScape is a Java-based Massively Multiplayer Online Role-Playing Game (MMORPG) operated by Jagex Ltd. It is a graphical browser game incorporating 3D rendering. The game has approximately 8.5 million active accounts and is recognised by Guinness World Records as the world`s most popular free MMORPG. RuneScape takes place in the game world of Gielinor, a fantasy-themed realm divided into several different kingdoms, regions, and cities. Players can travel throughout Gielinor on foot, by using magical teleportation spells and devices, or mechanical means of transportation. Each region offers different types of monsters, resources, and quests to challenge players. Players appear on the screen as customizable avatars, setting their own goals and objectives. RuneScape does not follow a linear storyline; players choose their own goals. Players can combat both monsters and other players, complete quests, or increase their experience in any of the available skills. Players interact with each other through trading, chatting, or paticipating in both combative and cooperative minigames.

The predecessor of RuneScape, DeviousMUD, was created by Andrew Gower in 1998. This was rewritten and renamed RuneScape, and released on 4 January 2001 in beta form. As the game`s popularity grew, the game engine was rewritten, producing a new product dubbed RuneScape 2, released in beta on 1 December 2003, and was renamed as RuneScape upon its stable release on 29 March 2004.

Players begin in a secluded area. They are led on a set path where they learn the most basic skills in RuneScape. After the tutorial, players have access to tutors located in the towns they explore. These non-player characters, or NPCs, can replace basic equipment items if necessary and can give players appropriate information about their respective skills. When the tutorial was introduced on 24 September 2002, it was set on a secluded island, often called "Tutorial Island". On 14 July 2008, a new tutorial was briefly introduced, set in the mainland town of Lumbridge, but due to technical difficulties with this new tutorial, the original tutorial was reinstated.

RuneScape features a real-time combat system. Combat is an important aspect of the game, allowing players to retrieve items or gold dropped by defeated creatures or players. Combat is also necessary to complete many quests. A combat level gives an indication of how powerful a player or NPC is in combat. For players, it is determined by applying a mathematical formula to the eight combat skills. Players engage in combat by clicking on the enemy they want their character to attack. A player character will automatically continue fighting until they kill their opponent, die, or leave the fight by running away or teleporting. Most of the game`s weapons are medieval or fantastical in nature and feature different strengths and weaknesses. Players may also summon a familiar to assist with combat, and use potions and the Prayer skill to boost their combat ability and defences.

Quests are series of tasks with a storyline that players can choose to complete. These often have prerequisites including minimum levels in certain skills, combat levels, quest points and/or the completion of other quests. Some quests require players to work together, and many require players to kill particularly powerful monsters. Quests are grouped into five categories based on requirements and difficulty. Once a player completes all quests in the game, an achievement cape, called the "quest point cape", can be purchased from an NPC. Generally, two new quests are released each month.