Abstract
In this paper we propose a solution to introduce a function for difficulty degree of achieving a simple, uni-dimensional goal of a level of an exergame. This solution, takes advantage of a statistical method built upon the results of the specific cerebral palsy (CP) player under study, inspired from normal distribution. It is appropriate for CPs, since it favors a content-based approach which is formed upon each player’s personal results. Using a population of 20 CP patients trying to achieve the goals of games, we arrived to an 85% correlation between number of goal achievement failures and our introduced difficulty function.