Introduction. Each change in the rules of a sport affects the way it is performed. Therefore, changes in regulations require that new training models be developed. The aim of the study was to determine whether FIBA’s introduction of new regulations in the 2010/2011 season pertaining to the dimensions of certain parts of the playing area, which changed the conditions under which the game was played, impacted the offensive actions of the top three teams in the Polish Basketball League. Material and methods. The study analysed qualitative data describing the offences (n = 16,694) performed during 200 matches of the Polish Basketball League, that is the highest-level men’s professional basketball league in Poland, during two periods: the 2009/2010 season (110 matches; n = 9,343 offences), before the regulations were modified, and the 2010/2011 season (90 matches; n = 7,351 offences), after they were changed. The research involved the players of three teams who received the gold, silver, and bronze medals in the final standings of the Polish National Championship in the 2009/2010 season. Results. The study found a statistically significant (p < 0.001) decrease in the overall number of tactical offensive actions of 3.84% and a significant (p < 0.05) 5% decrease in the mean number of points scored. A significant (p < 0.05) decrease in half-court offences, amounting to almost 2% was also observed. This offensive system was characterised by a minor shift toward individual offences with the back to the basket and pick-and-roll offences; these changes, however, did not cause an increase in the level of effectiveness. Conclusions. The direction of the changes observed have been determined, which consisted in a reduction in the overall number of offensive actions and a shift in the place where they were completed, from the three-point area in particular, to the two-point area.