The concept of immersion has been widely used for the design and evaluation of user experiences. Augmented, virtual and mixed-reality environments have further sparked the discussion of immersive user experiences and underlying requirements. However, a clear definition and agreement on design criteria of immersive experiences remains debated, creating challenges to advancing our understanding of immersive experiences and how these can be designed. Based on a multidisciplinary Delphi approach, this study provides a uniform definition of immersive experiences and identifies key criteria for the design and staging thereof. Thematic analysis revealed five key themes – transition into/out of the environment, in-experience user control, environment design, user context relatedness, and user openness and motivation, that emphasise the coherency in the user-environment interaction in the immersive experience. The study proposes an immersive experience framework as a guideline for industry practitioners, outlining key design criteria for four distinct facilitators of immersive experiences–systems, spatial, empathic/social, and narrative/sequential immersion. Further research is proposed using the immersive experience framework to investigate the hierarchy of user senses to optimise experiences that blend physical and digital environments and to study triggered, desired and undesired effects on user attitude and behaviour.