Virtual reality (VR) can create realistic behaviors in immersive environments through two key illusions: place illusion (PI) and plausibility illusion (Psi). PI refers to the feeling of being physically present in a virtual environment, while Psi is the illusion that events in the environment are real. Both illusions are crucial for participants to respond realistically to virtual scenarios. PI is influenced by sensorimotor contingencies (SCs), which are the actions that allow perception in the virtual environment. Psi depends on the scenario's credibility and how it relates to the participant. When both illusions are present, participants behave as if the virtual environment is real. Immersion in VR is determined by the range of SCs a system supports. Higher immersion systems provide more realistic SCs, allowing participants to perceive and interact more naturally. PI is maintained through SCs that mimic real-world actions, while Psi is supported by the scenario's plausibility and the participant's perception of events. The fusion of PI and Psi creates a virtual body illusion, where participants perceive their virtual avatar as their own. Studies show that PI and Psi can be measured through physiological and behavioral responses. However, these responses vary depending on the level of immersion and the type of system used. For example, in low-immersion systems, PI may require more mental effort to achieve, while in high-immersion systems, it is more automatic. Psi is also influenced by the scenario's credibility and the participant's expectations. The paper discusses the importance of both illusions in creating realistic responses in VR. It highlights the challenges in measuring PI and Psi across different systems and the need for a clear conceptual framework. The research emphasizes that Psi is more challenging to achieve than PI, as it requires a credible scenario and plausible interactions. The paper concludes that understanding and enhancing both illusions is crucial for developing effective VR applications, particularly in fields such as psychology and social behavior.Virtual reality (VR) can create realistic behaviors in immersive environments through two key illusions: place illusion (PI) and plausibility illusion (Psi). PI refers to the feeling of being physically present in a virtual environment, while Psi is the illusion that events in the environment are real. Both illusions are crucial for participants to respond realistically to virtual scenarios. PI is influenced by sensorimotor contingencies (SCs), which are the actions that allow perception in the virtual environment. Psi depends on the scenario's credibility and how it relates to the participant. When both illusions are present, participants behave as if the virtual environment is real. Immersion in VR is determined by the range of SCs a system supports. Higher immersion systems provide more realistic SCs, allowing participants to perceive and interact more naturally. PI is maintained through SCs that mimic real-world actions, while Psi is supported by the scenario's plausibility and the participant's perception of events. The fusion of PI and Psi creates a virtual body illusion, where participants perceive their virtual avatar as their own. Studies show that PI and Psi can be measured through physiological and behavioral responses. However, these responses vary depending on the level of immersion and the type of system used. For example, in low-immersion systems, PI may require more mental effort to achieve, while in high-immersion systems, it is more automatic. Psi is also influenced by the scenario's credibility and the participant's expectations. The paper discusses the importance of both illusions in creating realistic responses in VR. It highlights the challenges in measuring PI and Psi across different systems and the need for a clear conceptual framework. The research emphasizes that Psi is more challenging to achieve than PI, as it requires a credible scenario and plausible interactions. The paper concludes that understanding and enhancing both illusions is crucial for developing effective VR applications, particularly in fields such as psychology and social behavior.