This article addresses the issue of foreign language testing in the online mode and proposes a strategy to reduce the possibility of academic misconduct, specifically cheating, by designing tasks that assess the language skill of mediation in Legal English exams. Such tasks require test-takers to generate original answers, which can significantly reduce the risk of copying and pasting. Additionally, mastering the skill of mediation is a valuable asset for future lawyers. The authors introduce two original distinct intra-language mediation tasks that they developed for assessing English for Legal Purposes. One is aimed at first-year students with limited Legal English experience, while the other is intended for more advanced and experienced students. The article analyses student responses and evaluates their performance. The authors follow the action research approach, which involves a circle of observing, reflecting and acting, and raise questions concerning the originality of answers, production of a measurable sample of the target language, objectivity of assessment, and whether the practice in class impacts the success rate. The article also discusses challenges encountered during the process and how they were addressed. It can be concluded that mediation tasks are practical for online testing but could be used equally well for traditional classroom assessment.