The paper analyses athletes' behaviour within the competitive sports and focuses on two cruxes in meaning on the scale between behaviour in the spirit of sports and unfair play: sportsmanship and gamesmanship. Using the method of phenomenology, an invariant characterizing precisely the denotates of both notions was sought.
Both practical examples from sports competitions and some previous interpretations from the field of sports ethics were utilized. A certain vindication of gamesmanship was one of issues: it cannot be joined only with negative connotations ("unsportsmanlike conduct") - it has a specific intersection with both sportsmanship and classical notions agon and arete.