Despite the growing interest in emotions in engineering education, empirical research on incorporating them into engineering ethics education is limited. Therefore, we designed this experimental study to assess how different methods for integrating compassion into engineering ethics cases influenced the intensity of compassion associated with the protagonists of the cases. We utilised modified versions of the Engineering and Science Issues Test (ESIT) cases, employing three methods to intensify compassion associated with the cases' protagonists: (i) implicit induction, (ii) explicit expression, and (iii) through the description of severe consequences. The participants (n = 415), predominantly engineering students (90%), were divided into one control group and three experimental groups. Results indicated that all three methods increased the intensity of compassion in the cases. However, the implicit method had a relatively weaker impact than the other two methods which had similar effects on the intensity of compassion. Other emotions did not seem to be impacted by the changes. This study provides valuable insights into effective methods to increase the intensity of compassion in engineering ethics cases without affecting other emotions.