I hear this all the time and I have no clue what ELO is. I've been playing league for almost a year now and have gotten to level 30 about a month or two back. I've never heard it discussed before I was level 30, and am really confused on what it is, and how to raise/lower it, etc. Help me out here?
ELO is the score used in the matchmaker to pair you up with other players of similar skill. Ideally you'll pair with 9 other people with your exact ELO, but connection strength, region, duo quing, etc. this usually doesn't happen.
You raise you ELO by overcoming people of equal or higher ELO than yours, and you lose it by losing to people equal or lower than you, with varying effect depending on the actual difference. As such, "ELO hell" is where you can never gain ELO to play with and against better people due to where your ELO is currently.
Ranked, 3v3, Dominion and Normals all have separate ELO scores, Draft and Normals share one. There isn't a reliable way to check your actual ELO score, just approximations, but I suggest using your Lolking score as a gauge for your standing. Most do.
ELO is a global ranking system. It was first used in chess competitions.. 1200 elo rating is the average, while above 2000 are masters. (see http://en.wikipedia.org/wiki/Elo_rating_system)
On that game though, Elo is quite weird, since this ranking system was made for individual skills ranking (chess, starcraft, any 1v1 game). Though, this is a team game.
Anyhow, to gain Elo you must play ranked games.. If you win, you gain 15-20 elo and LP (League points are NOT related to Elo at all!), if you loose games, you loose elo acordingly. It is that simple.
League points though are a little misleading, since those ranks ("bronze, silver, gold, plat, diamond") actually are fake. You always have your "hidden elo" which is your real rank.
Little tip : Don't be scared to dodge games (close the LOL client while in team select) since your MMR (hidden elo) doesn't get hindered by that, though your LP while drop by 5 LP or 10 LP. But it doesn't really matter since your LP gain is based on your MMR.
Sorry about the random rambling, but that quite sums it, if you have precise questions, you can ask them to me in a reply and I'll try to answer them to my best knowledge.
Sifu
ELO was the system used to describe your ranked stats before the whole tier system (current one) was in place. basically higher the elo, higher your league is and your win raises it loss lowers it.
