A more motivating way of introducing students to probability theory is through real-world problems. Since heuristics play an important role in our probabilistic judgement, knowing how to avoid incorrect probabilistic reasoning, which leads to several biases, could help students to develop more critical thinking skills. In this paper, we present a different way of introducing students from a linguistic lyceum (high school) in Italy to probability theory. In our laboratory, we introduced students to the three most studied heuristics: representation, availability, and anchoring. The aims of our laboratory were two-fold: (1) motivate the students to learn probability theory through the presentation of the most common mistakes (biases) that are made due to erroneous probabilistic judgements; (2) increase students' awareness of the "tricky" questions that could be present in the national assessment of knowledge of mathematics for grade 10 students. The results of our laboratory show an increase in students' participation in the class activities, as well as increased motivation.