The Bebras International Contest on Informatics and Computer literacy is a motivation competition in informatics that addresses all lower and upper secondary school pupils divided into three age groups: Benjamin (age 11-14), Junior (age 15-16) and Senior (for upper secondary level). Using a computer the pupils have to solve 15 to 21 tasks of different levels within 45 minutes. Two general types of of problems have been used: interactive tasks and multiple-choice tasks. Creating interesting and attractive tasks that are also motivating and funny for the pupils is very challenging. The paper deals with criteria for good tasks. Some examples of tasks are presented and discussed as well.