This paper explores ways the classroom environment can fertilise ethnic and religious tolerance in students. In a pre/post test design, 76 students at a university secondary school in the Niger Delta region of Nigeria were randomly selected to respond to a twenty-item survey. Afterwards, the experimental group was exposed to a critical thinking game that focused on rational appraisals of ethnic and religious prejudices. A t-test analysis indicated a significant difference in prejudice between the experimental and the control group. It was concluded that classroom language experiences could foster positive changes in ethnic and religious prejudices.