This study presents the results of an experiment on determinants of the strategy used by the participants and their profi tability. The study was based on N-person games in normal form 3x3. All games have clearly defined theoretical solution (the unique Nash equilibrium, which can be reached using the iterated elimination of strictly dominated strategy).The most important conclusion that can be drawn from this analysis is the failure of the theoretical model predictions based on Nash equilibrium. The use of non-equilibrium strategy for people with relatively little theoretical knowledge was due to the inability to find such a strategy. However, participants with a relatively high theoretical knowledge use non-equilibrium strategies deliberately expecting higher profi t. That is why theoretical knowledge is useful, but its use should be adapted to the situation in the real world. This enables players to achieve extra profits.