I think Csíkszentmihályi's theory of Flow adescribes a real psychological phenomenon of energized involvement, and that's what is referenced by "immersion".
Photo-realistic graphics, 3D sound, emotional events, deep characters, and other elements are means of achieving immersion and are thereby important and can be described as "immersive". But, for instance, AAA graphics are immersive not because they actually fool us into thinking they are real, but because they make it easier for us get actively absorbed.
I think you are going wrong from the get go when you set up this standard: "I know I've never had an experience involving any medium -- movies, video games, flight-simulator-style amusement park rides, pen-and-paper roleplaying -- that I didn't recognize as mediated." It isn't about whether you rationally recognize the experience as mediated, but whether you emotionally respond to the experience as mediated, or if you relate to it as if it were an actual experience. If it's the latter, that is testament to immersion.
When I recall gameplay from MMORPGs and pen and paper RPGs, I tend to recall it (and describe it) as if it were a vacation or real-world incident. "Do you remember that time when we stormed the Lich King's manor, and Romodred got his arm cut off?" I genuinely don't remember it or describe it as "remember that time when were sitting around a table and Jon rolled a 1." The scene in my head of what we were playing at has replaced the actual events. That's testament to immersion.
If you *don't* get that experience, I'm not sure what appeal a pen-and-paper RPG would even have, other than as a B.S. session with friends over beer and pretzels.
Photo-realistic graphics, 3D sound, emotional events, deep characters, and other elements are means of achieving immersion and are thereby important and can be described as "immersive". But, for instance, AAA graphics are immersive not because they actually fool us into thinking they are real, but because they make it easier for us get actively absorbed.
I think you are going wrong from the get go when you set up this standard: "I know I've never had an experience involving any medium -- movies, video games, flight-simulator-style amusement park rides, pen-and-paper roleplaying -- that I didn't recognize as mediated." It isn't about whether you rationally recognize the experience as mediated, but whether you emotionally respond to the experience as mediated, or if you relate to it as if it were an actual experience. If it's the latter, that is testament to immersion.
When I recall gameplay from MMORPGs and pen and paper RPGs, I tend to recall it (and describe it) as if it were a vacation or real-world incident. "Do you remember that time when we stormed the Lich King's manor, and Romodred got his arm cut off?" I genuinely don't remember it or describe it as "remember that time when were sitting around a table and Jon rolled a 1." The scene in my head of what we were playing at has replaced the actual events. That's testament to immersion.
If you *don't* get that experience, I'm not sure what appeal a pen-and-paper RPG would even have, other than as a B.S. session with friends over beer and pretzels.