http://www.riotgames.com/internships
All the information is in the above link
There is a lot to read
Note, they're only accepting students in a college program. You have to be a full-time student enrolled in an accredited undergraduate or graduate degree program. Riot Games prefer students looking for internships during the summer before their final year.
This has its own thread because it's serious and some people might want to slave away at Riot Games (thats what interns are for although these are paid internships)
Available positions:
Art Intern
Business Intelligence Intern
Communications Intern (graduate-level only)
Development Operations Intern
Engineering Core Services Intern
eSports Intern
Game Design Intern
International team Intern (graduate-level only)
Live Services Intern
Player Research Intern
Video Production Intern
Important things:
-You have to work there. Not at home
-No work visas will be provided for internationals
-If you're invited for interviews, Riot will cover the flight, accommodations, food and transportation.
-According to Riot Games, you will be paid enough to pay for your own housing.
-Estimated 60 hours/week work
-Your summoner account must be at least level 12