What’s new, Riot?
Despite its massive player base and roaring esports scene, its servers are nothing to write home about. They tend to malfunction, kicking players out from matches or preventing them from joining altogether. If Summoner’s Rift isn’t down, it’s the client or even the store.
Sometimes it’s difficult to determine whether the issue is on Riot’s end or yours. Thankfully, there are a few easy methods to check if League is down.
Riot’s official service status

If you suspect League is down and you can’t connect to the client or join a game, then checking out Riot’s Service Status page is your best bet.
It’s not always totally accurate, but it should give you a good idea of what’s happening. If everything is in working order, it should say, “No recent issues or events to report.”
Downdetector

Another good way to see if League is down is by checking Downdetector, a real-time problem and outage monitoring website.
The website shows a comprehensive timeline of server issues in the last 24 hours. If League is down, then the site will likely have an influx of reports, as well as comments in the comment section below. If not, the issue is likely on your end.
It also has a handy Live Outage Map, pinpointing server issues in each country.
Lastly, just to make sure, you can check Riot Games Support on Twitter. If there’s a major issue with the League servers, Riot will tweet about it.