Riot Games pulled out a rabbit out of the hat by releasing Ruined King: A League of Legends Story all of a sudden. While that comes as a surprise to the entire gaming community, many have been wondering if it's important to play League of Legends first.
The name of the new game quite literally says a "League of Legends Story" so it's not difficult to understand why everyone would assume that it's important to play League of Legends first. However, that might not be the case.
Do you need to play League of Legends before moving on to Ruined King?
Since it's a part of the League of Legends universe, the characters and world are the same, yes. However, Ruined King has it's own story and it's more like a lore note for the League of Legends game.
That being said, if you're worried about not being able to keep up with the storyline, you needn't because Ruined King has it's own set storyline that it follows. If you do want to make sure you have a head start on the story, all you need to do is read the lore notes in the League of Legends client.
Moreover, although the characters are same and it'll help a bit if you've played League before, Ruined King does a pretty good job at giving an in-depth information about the characters.
Overall, Ruined King: A League of Legends Story does a pretty good job of holding its own ground when it comes to the storyline and everything. So the final verdict is No, you don't need to play League of Legends before diving into Ruined King.