Trained in English law and Called to the Bar of England and Wales, Leon holds a PhD in video game law, focusing on the regulation of loot boxes, gacha, and other gambling-like monetisation mechanics in video games that offer random rewards. Using empirical legal research, he assesses compliance with regulations across various countries and advises on improvements. He also conducts traditional, doctrinal legal research and psychology studies, including surveys and experiments. He is passionate about open science: he preregisters research methods, shares data, and even conducts registered reports (including likely the first one in the world in the legal discipline).

He actively advises on global policymaking and has testified before an Australian House Committee. His research has been referenced (twice!) in the House of Lords, cited by the US Federal Trade Commission, and various European regulators, influencing compliance actions by companies. His award-winning research has received worldwide coverage in over 670 media features by The Guardian, The BBC and The Times.

Recognized as a Forbes 30 Under 30 and a Berlingske Talent 100, Leon continues to impact video game policy.