As esports has gained a growing audience, parents and educators have raised concerns about deviant behaviors associated with it (tilt). The present study investigated players’ stress levels and emotions around in-game stress events by means of physiological measurements (heart rate [HR], heart rate variability [HRV], and facial expressions) to find out how in-game stress events affect player’s stress levels according to different groups of players and different event contexts. While groups of young players (N = 119) aged 14-25 played three matches of League of Legends, their in-game logs, video recordings of gameplay, in-game communication, and physiological data (HR, HRV, and facial expressions) were collected. Linear mixed-effects models were fitted to explore the effects of different player groups and in-game contexts related to the stressful events during the gameplay. The higher game skill level and later in-game phase were positively associated with earlier recognition and anticipation of upcoming events before they occur. Winning a match, later in-game phase, Enemy and Myself events were positively associated with a higher increase of HR during a stress event. Older age and Team and Teammate events were positively associated with a smaller decrease in HR after stress events. Lower game skill level, older age, and later in-game phase are associated with a bigger drop of HRV during stress events, which implies higher stress levels. Overall, the contribution of this study lies in exploring the in-game variables that impact player tilt employing physiological measures of players’ emotions.