Many people have lamented that videogames do not have the fictional depth that can elicit real emotion. "When will a videogames make us cry?" they ask. Movies, theater, and literature can make us feel happy or sad, but these media have hundreds and sometimes thousands of years of experience in perfecting the storytelling methods that work for each medium's strengths and weaknesses. Gaming is young by comparison, but I think that one form of game has the ability to make the player feel something strong. It's just not the emotion that everyone is shooting for.
Dungeons & Dragons allows player agency better than any videogame; we as players choose to do the things that our characters accomplish. Because of this, players are free to experience the emotions that are the consequence of our actions. We feel sadness when someone is lost. We feel triumph when we defeat the big bad guy. We feel anger and frustration when we are betrayed.
Usually, it is the Dungeon Master who creates the situations that elicit these emotions. Through roleplaying every other character in the campaign or session, the DM becomes both confidante and adversary. I've had sessions where I've played a male character speaking to a female priestess where I completely lost sight of the fact that the "female" was my friend Bill. When a game can do that, when the game becomes a reality simulation, then a broad spectrum of real feelings can be felt by the player.
In one game that I played in New York City, I chose to play a young kid in a big metropolis whose father was the only family that he had. Pyrano was experiencing changes (turning into a dragon, actually), and his father was the only connection to his old life. Through the course of the first few adventures in the city of Sasserine, Pyrano would check in at his father's esoteric shop of wondrous items quite often. I would ask my father about the changes that were happening to me. At first, the DM assumed that I was talking about the draconic changes and concentrated on the mechanics, but then he began to play a more father-like character and offered advice on becoming a man. The draconic changes became a metaphor for adolescence. Though we would only roleplay it a few minutes of every session, it felt like an ongoing relationship that meant something to both me the player and the DM, a new father.
That's why it felt so powerful when I had to leave him. The adventure storyline was moving to the Isle of Dread, and Pyrano was going to travel with his friends. Saying goodbye to Pyrano's father felt like a son leaving to go to college. All of the advice and recommendations he gave me would be put to the test but he would no longer be there to watch it happen. I felt all of the conflicting emotions of growing up - excitement, trepidation, responsibility - even though I was in my late twenties and married at the time.
Last night, something occurred in my weekly old school D&D game that also had a profound effect on me. Our group has been trying to stave off the Dark Dawn, wherein every "undead" would rise and kill us "normal" people, almost since I joined the party. The DM has created a rich open world that is driven through player choice. There is no railroad, but we have been choosing to try to stop the Dark Dawn in incremental steps because it behooves us as player characters. The undead apocalypse isn't good for anyone.