The intervention group gain access to the game after filling in the baseline online questionnaire. The participants are asked to play at least two characters in the game. They have two weeks to play the game.

Waitlist control group

A serious game to improve mental health in youth

A 90-item self-report instrument measuring seven adaptive, five maladaptive, and three external emotion (sadness, anger, and anxiety) regulation strategies. Each item is rated on a 5-point Likert scale from 1 = almost never to 5 = almost always. The score on the adaptive (ranging from 42-210), maladaptive (ranging from 30-150) and external (ranging from 18-90) subscales are considered. The higher the score on a subscale, the greater the disposition to cope with negative emotions in a certain way.

3 subscales on cognitive coping strategies (i.e., optimism, control, and seeking understanding) are used. Each subscale has 4 items and all items are scored on a 4-point Likert scale from 1 = never to 4 = most of the time. For each subscale the minimum total score is 4 and the maximum score 16. The higher the mean score on the subscale, the more often the cognitive coping strategy is used.

14 statements regarding the effect, content and usefulness of the game. Items were rated on a 5-point Likert scale (1 = 'completely disagree'; 5 = 'completely agree').