After applying on their website, I received a call from a recruiting coordinator to schedule a screen interview a day later. The beginning of the call focused on summarizing my previous experiences, featuring your relatively standard interview questions. The rest of the call focused more on culture fit. Riot is very well known for having an awesome culture, and a great community focused on a 'by gamer, for gamers' mindset. Having lots of experience in teamwork environments, and being an avid gamer, it seemed I would fit well within the culture, to which they agreed. My weakness coming in was my lack of experience with their feature game, League of Legends. They wanted me to familiarize myself with the game and its culture before pursuing my application further, so they asked me to reach level 10 in the game and to contact them afterwards.
This took me a few days to reach, and the communication during so was great. My recruiting coordinator openly told me to ask him any questions that may come up during my play - and he would answer them personally - again a great look into how much this game means to them.
They then set me up with a manager from the department I would be working in. The questions became much more job-specific, and were much more in-depth. Despite that the conversation was still very enjoyable and casual. We spent time talking about the job, real-life scenarios, more detail into Riot culture, and chatted about some highlights of the game.
A few days later the same manager emailed me stating they would be pursuing my application further. They were very nice and broke down the reasoning behind their decision, a nice personal touch. They also discussed what the re-application process would look like if I continued to be interested later on. They even offered me another phone call to further break down their reasoning - again, a nice touch that too many employers overlook.
Overall I had a great experience interviewing with them. While the atmosphere and culture of Riot is very casual, and relating to it is very important, it's even more important to not forget why you're on the phone with them - to sell yourself and tell them what you can do to better the company.