What is Elo?
 | Your Elo is essentially your rating. It is determined by your win/loss ratio and how many games you have played. In normal queue your Elo is hidden from yourself and others, but the matchmaking system still uses it to decide your opponents. In ranked games your Elo is there for the world to see, with Iron being the lowest and Challenger being the highest. |
Contrary to popular belief, "ELO" isn't an acronym nor was it invented by Riot Games. The Elo rating system was made by Arpad Elo, who named the system after himself. It was originally used as (and still is used as) a rating system for chess players, and will most likely use exactly the same algorithm to calculate their skill level, though it will be a close variant if not exactly the same. You can read more about Elo and its creator here upon its Wikipedia article.
League of Legends still uses a form of a ranking system which is inspired from the Elo system called the League system, matching players of a similar skill level to play with and against each other. It comprises nine tiers which indicate the skill level of players. Players within each division are ranked using a system of points called League Points (LP). Everytime you play a game, you will either lose or win LP depending on if you lost or won the game, the more LP you get, the higher in Elo you will be able to climb.
Down below is a representation of all the ranks that are currently in League of Legends. Having Iron being the first one on the left side, then Bronze, Silver, Gold, Platinum, Diamond, Master, Grandmaster and finally ending with Challenger.
