For many people it is very difficult to find a group that some would deem a full party of adventurers to play Tabletop RPGs. When I got into gaming this was the case for me. I struggled to find people to play Heroes Unlimited which for me this was the game that I loved when I was 12 and loved up until recently. My first RPG group was 2 players and a GM. When the GM moved it made it near impossible to game because we had it in our mind you needed multiple players to play the game properly. If we only knew about the possibility of playing with 1 player and a GM our RPG experience would have been drastically different.
The 1 player and 1 GM format I have seen called different things. I have seen it called 1 on 1, solo, and duet campaigns. What the actual correct terminology is I am not quite sure. What I do know is that this is a great way to run and play games for those of us who may struggle to find groups to play with. Some people use these types of games to help players catch up after mission a session. Some people use these types of games to teach a new player how the game is played. Either way it is a great way to game and can provide a vastly different experience than you may be used to.
A few years ago I attempted to run a Heroes Unlimited game like this for my wife. Our first session was a lot of fun. She played a Mega Hero that we rolled a lot of the stuff randomly. That character ended up being very similar to Thor which was pretty interesting. The idea of those first few sessions was that she had no idea how things worked on Earth. She broke an elevator door and beat 2 guys into a coma when they tried to kidnap her. Unfortunately the campaign didn't last very long because we ended up moving.
We tried again to do another duet campaign using Pathfinder when I was really getting into that system. The idea was that my wife would make and control a few characters. Her party was an Aasimar Sorcerer and an Oread Barbarian. We played a couple games and this was fun but we wanted enough players for a full party. This game died off but only because once again real life stepped in and we moved again.
There are many ways to play a game with one player. Maybe that player controls only a single character or they control a whole party of characters similar to how they would play a video game like Baldur's Gate. Maybe they handle all of the groups social interactions with NPCs or maybe they only control their single characters social interactions while the DM controls all of the other members of the group in social environments similar to Dragon Age for example. In the latter example the players choices could lead to some members of the party leaving the group. No matter how you choose to play this can be an extremely fun way to game.
This style of play is one I wish I was able to try sometime. I would love to play both as just a single character without a party and also a campaign where I play as a single character but in combat I can control a whole party. If I had a DM who was good at improvising I think this could be one of the most enjoyable ways for me to play a game.
On YouTube there are at least 2 channels that cover this style of game. Matt Click's afistfulofdice on YouTube and has recently started running games on his channel for his fiance. He is also my DM for the Provokers campaign and is a very good DM. Andrew Armstrong known as DawnforgedCast has a couple games in this style on his channel. One is with his wife, and the other is with one of his viewers. To see how these games can be played go and check those channels out. If you are interested in running or playing a game in this style feel free to join the Tabletop RPG One Shot Group and seek it out.