The example that immediately comes to my head is Runescape. The game is free for everyone. If you want more access to the world, you need to pay for a monthly

The example that immediately comes to my head is Runescape. The game is free for everyone. If you want more access to the world, you need to pay for a monthly subscription. Note that this is not like the item mall games because in Runescape you pay for access to more content. You still have to work to get new items/skills like the free players. (although you can sometimes accomplish things more easily compared to a free player)