The "physics behind the laser tag" deals with the sub-field area of study known as Optics. Optics is the study of the behaviour and properties of light. It is a branch of the physical sciences. Sir Isaac Newton, the world renowned British physicist, wrote a book on the material labeled "Optiks," that was released to the public in 1704. Refraction is also a very significant concept when it comes to the "physics behind the laser tag." Refraction is the bending of light rays ( the laser of the laser gun in this case) as it passes between two different "medium" (2 medium makes up a "media"). The 2 medium in this case is the wall and the room adjacent to the wall. A good idea for introducing your class to this inter discipline of physics would be a PowerPoint or a practical science-fair themed like project with a Hypothesis and all that sort of stuff. Also, remember that a science paper project must be written in APA format (which shows subscripts and superscripts). It also must be very clear and concise, and all the concepts must be explained accurately.