This paper describes intervening conditions that might constrain or facilitate the exercise of Legitimate Influence: The Key to Advanced Nursing in Adult Critical Care, the foundation of which is credibility and advanced clinical nursing practice. Constraining conditions are conflict, resistance, gender bias, political awareness and established values. Credibility, advanced clinical nursing practice and strategic activity are required to enhance patient stay in hospital and improve patient outcome. Intervening conditions that facilitate these are overcoming resistance, political awareness and established values. In a previous paper, it was indicated that enhanced patient stay and improved patient outcome were achieved primarily through strategic activity that emphasized restoring patients to a former, or improved, health status. This paper portrays how intervening conditions can impinge upon this and the exercise of legitimate influence.