Pros
-Fantastic autonomy to get things done. -Great perks (gym, 401k match which immediately vests, game allowances, on-site food), fantastic office. -Yearly company vacation. -People here are truly passionate about what they do. -A game company run by gamers and for gamers. -Interesting technical challenges. -Long-term opportunities abound. -Entrepreneurial people will thrive here since you're given so many chances to choose your destiny.
Cons
Some groups have very poor middle-management. Some managers at Riot are first-timers and have been promoted from other roles; they learn while on the job which comes at the expense of those they manage. It's a bit of a crap shoot when you're applying for a job who your manager will be, how proficient they are at managing people. If your manager is poor and not receptive to feedback, there's no way of escalating in a way that protects you from retaliation. Your manager controls your salary and your employment is at-will, so sugar coating feedback is a risk. Note: poor managers and groups are fewer in number than the good ones. I expect Riot will weed them out over time, but it doesn't appear to be a priority right now during our fast growth phase. Riot has done a good job defining company and player values, but has ignored team and employee values, leaving to an inconsistent experience based on where you land.