Runescape Classic, originally just called Runescape, is the precursor to Runescape 2 which according to the Guiness Book of Records, is the largest free-to-play MMORPG in the world, with over 10 million active accounts and 130 million registered accounts.
An account created for Runescape Classic will also allow the player to play Runescape 2, although items are not transferable between the games. New accounts can no longer be created specifically for Runescape Classic, although occasionally players are allowed to play the Classic version using their Runescape 2 accounts.
The game is very open-ended, leaving the player with a huge choice of what to do. As with most MMORPGs there are quests to complete, NPCs to battle, treasure to find, trade and sell, and a large number of minigames to play. There is also player-vs-player combat, but this is entirely optional and avoidable if so desired.