Nelson Zagalo's presentation on gamification discusses how to effectively motivate and persuade individuals to engage in activities through design, emphasizing autonomy and user behavior modeling. He highlights the importance of triggers such as relatedness, progress, scaffolding, feedback, cliffhangers, scarcity, reciprocity, and conformity, referencing theories by Deci, Ryan, and others. The case study of Fortnite illustrates the application of these gamification principles in enhancing user experience.