Principal Research Scientist

Research Scientists at Riot combine deep technical expertise across machine learning, artificial intelligence (AI), experimental design, and systems engineering to invent new ways players experience games. As a Principal Research Scientist, you operate at the frontier of what’s possible and set the standard for how research is conducted and how it translates into extraordinary gameplay.

As a Principal Research Scientist in Tech Research, you will lead a small, cross-functional team focused on building AI-powered gameplay prototypes. These prototypes are not paper exercises, instead they are playable, opinionated explorations of new game mechanics, agent behaviors, and player experiences enabled by modern AI. You will be responsible for identifying promising research directions, translating them into concrete gameplay experiments, and driving them from early concept through working prototypes that influence game teams. You will be the technical and creative lead on complex, ambiguous problems where success requires strong judgment, rapid iteration, and an ability to balance research rigor with hands-on building. You will set the vision and quality bar, leading by example in various capacities, including writing code, shaping robust systems, and mentoring team members. You will lead AI-driven gameplay exploration who is tasked with rapidly testing new ideas through playable prototypes, rigorous evaluation, and real player insight. Your team will identify emerging research with the potential to meaningfully change gameplay, turn it into concrete gameplay experiments, and work with game teams to transform validated breakthroughs into options Riot can confidently commit to.

Responsibilities:

• Define and lead AI-powered gameplay research directions, translating emerging ML/AI capabilities into concrete, playable game prototypes
• Build, lead, and mentor a small cross-functional team, setting technical direction while remaining deeply hands-on
• Own research and prototyping roadmaps, milestones, and risk management for multi-quarter initiatives
• Work closely with game teams to understand player goals and design constraints, ensuring prototypes are grounded in real gameplay needs
• Rapidly iterate on prototypes, balancing research rigor with playability, performance, and developer usability
• Stay current with academic and industry advances in AI for games, reinforcement learning, generative models, and agent systems
• Communicate vision, progress, and learnings clearly to stakeholders, helping teams understand both what works and what doesn’t

Required Qualifications:

• MS in Computer Science or equivalent with 6+ years research experience or BS in Computer Science or equivalent with 8+ years research experience
• Strong background in applied or foundational research, with experience leading projects through hypothesis-driven experimentation
• 2+ years of experience in machine learning for sequential decision-making, agents, or complex systems (e.g., RL, imitation learning, planning, or hybrid approaches)
• Proficiency in C, C++, or Python
• Demonstrated contributions to public research (e.g., publications, talks, open-source projects)
• Experience designing and implementing complex systems that integrate ML with real-time or interactive environments
• Expertise with PyTorch or TensorFlow
• Experience working in commercial game engines for prototyping or production
• Strong understanding of gameplay systems, game loops, and real-time constraints
• Experience collaborating closely with designers and engineers in a game development context

For this role, you'll find success through craft expertise, a collaborative spirit, and decision-making that prioritizes the delight of players. We will be looking at your past studies, experience, and your personal relationship with games. If you embody player empathy and care about players' experiences, this could be your role!

Our Perks:

Riot focuses on work/life balance, shown by our open paid time off policy and other perks such as flexible work schedules. We offer medical, dental, and life insurance, parental leave for you, your spouse/domestic partner, and children, and a 401k with company match. Check out our benefits pages for more information.

At Riot Games, we put players first. That mission drives every decision in our quest to create games and experiences that make it better to be a player. Whether you’re working directly on a new player-facing experience or you’re supporting the company as a whole, everyone at Riot is part of our mission. And just like in our games, we’re better when we work together. Our goal is to create collaborative teams where you are empowered to bring your unique perspective everyday. If that sounds like the kind of place you want to work, we’re looking forward to your application.

It’s our policy to provide equal employment opportunity for all applicants and members of Riot Games, Inc. Riot Games makes reasonable accommodations for handicapped and disabled Rioters and does not unlawfully discriminate on the basis of race, color, religion, sex, sexual orientation, gender identity or expression, national origin, age, handicap, veteran status, marital status, criminal history, or any other category protected by applicable federal and state law. We consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with applicable federal, state and local law, including the California Fair Chance Act, the City of Los Angeles Fair Chance Initiative for Hiring Ordinance, the Los Angeles County Fair Chance Ordinance for Employers, the San Francisco Fair Chance Ordinance, and the Washington Fair Chance Act.

Per the Los Angeles County Fair Chance Ordinance, the following core duties may create a basis for disqualifying candidates with relevant criminal histories:

• Safeguarding confidential and sensitive Company data
• Communication with others, including Rioters and third parties such as vendors, and/or players, including minors
• Accessing Company assets, secure digital systems, and networks
• Ensuring a safe interactive environment for players and other Rioters

These duties are directly related to essential operations, safety, trust, and compliance obligations within our organization. Please note that job duties may evolve based on business needs and additional responsibilities may be assigned as necessary to maintain operational efficiency and security.