I've just finished running my first session with only one player, and it felt pretty different from running a session for a group.
Could someone with more experience in this talk about what one should do differently in that situation?
I'm not referring to mechanics like encounter-building, but focus on how to handle the change to the social dynamics.
Your comment on another answer implied you wanted to hear more about play style, pacing, and social dynamics, so I'll take a (long, it turns out) stab at that.
Spend a lot of time with the both of you discussing what the character wants to accomplish. Continually checking in and talking about the character's (and player's) objectives during the game will naturally help with pacing and allow you to keep an eye on the big picture, while highlighting the places in that big picture that you both find interesting to zoom in on.
Just as importantly, keeping the big picture and those goals in mind will put the focus of the game on the character, and it will help you, as GM, to concentrate on playing a supporting role to the character's unfolding story. The best part of being the player in a 1-on-1 game is being able to really dig into a character and push for their goals, so enabling this is a high priority.
Although pacing will probably come naturally from the big picture, if you expect to jump around a lot that will help you make the shift from a party-based style of play to a 1-on-1 style. Rather than allowing the game to move moment-to-moment (which gives a group of players lots of opportunities to all contribute), take the freedom of only handling one PC as an opportunity to hone your scene-framing skills. Tightly focus in on the points of conflict and character development (which won't always be the same thing) so that you can quickly get to what the meat of the character's story is right at that moment.
You might worry that such tight scene framing might miss out on those great "slice of life" parts of roleplaying that emerge organically when you play with looser, moment-to-moment scene framing, but you can have it both ways. Frame focused scenes that are deliberately about letting the character unfold, with or without a conflict. Put them in their home for a few minutes (for example), ask the player, "What's it look like when you first walk into your own home?" Let the player explore their character and interact with their environment for just a bit, to enjoy the experience. Such focused scene framing is possible without feeling artificial because in a 1-on-1 game you'll both get to know the character very well, quickly, allowing you to frame scenes that are just "obviously" interesting and relevant.
Other answers have mentioned that 1-on-1 games can be exhausting and you can get a lot done in them. Use variations in your pacing to build in breathing space where you can both relax and recuperate from the more intense parts of the game. After a tough scene, pull back and look at the big picture for a bit. Don't be afraid to let the game sort of meander occasionally just to get a break from such high-impact scenes. Make a point to pull out of roleplaying mode and chat about what just happened after particularly affecting stretches of game. While this would arguably be "wasting time" in a group game, you'll find that you cover so much ground in a 1-on-1 game that not only will you have time for it, but it will sometimes be necessary to properly appreciate what just developed, let alone think about potential repercussions.
I find the physical situation of roleplaying and looking straight at each other's faces is often be too intimate when playing 1 on 1, so I like to have a shared map or other visual reference that's between us, or that we're at 90 degree angles from one another both facing the map.
Both the player and GM should have things they want out of the game. They should be very up front and clear about those. If the player is thinking about the Stallone remake of Get Carter, and the GM wants more of lost soul on a Lovecraftian island, there needs to be significant negotiation.
I'd also use a ruleset that's really strong for 1 on 1 play, and that you're very comfortable with. S/lay w/me jumps to mind, but there are beginning to be more and more indie games tailored for 1 on 1 play.
If you are adapting a party-based system to one character, I would suggest keeping the reward cycle flowing quite fast. The PC is the star, so it's OK if they're a big mover and shaker in situations. The real fun comes from the consequences of those decisions.
I think, in a case like that, it makes sense to a certain extent to tailor the story to that player's character.
Think about the kind of character they built, and let their decision and their abilities drive the adventure. This is more than just a question of game mechanics. If they play a ranger, the events of the game can center around what's happening in their forest, and nearby villages. Use it as an opportunity to develop the character in detail. Challenge the character by letting them use their abilities in unorthodox ways, and presenting them with obstacles appropriate to their nature. Remember, that one player is the hero in his or her own story. Let the player's imagination drive the story, too.
In literature, a side character who helps show something about the main character is called a foil. Let your main NPCs reflect different aspects of the character. Some examples:
I'm not entirely sure if this answers your question; but, I hope you find it helpful and interesting.
Tailor the game to the two of you. You have opportunities that are not possible with a larger group.
My primary experience with 1:1 gaming is with my spouse of 15 years. We played RPGs intensely the whole time. The game was heavily tailored to exactly what each of us wanted to get from the experience. So all manner of interesting stories and changes were possible. That level of intensity is something special and, for those who have spouses who game, I highly recommend it.
In 1:1 gaming with a friend the emotional intensity is toned down a bit and adult themes tend to get much less of a spotlight. Still, you have an unique opportunity to tailor the game to fit the desires of this one player and can have a number of experiences that just aren't possible in a group. Assuming leadership or noble positions in society tend to be easier with a 1:1 session. Likewise, playing someone outside the law and society is also easier with a 1:1 session. So take advantage of the opportunity.
I have run a few one GM, one player games and they are really intense, almost tiring for the player especially. I found most players were pretty well cooked after two or three hours of that kind of play.
I like the character to be injected into a situation where there are lots of NPC's to interact with...a city filled with a colorful criminal underworld, a complicated tribe living under a monster-haunted mountain, etc.
As with most games, I want a prominent situation, something that really sends the campaign off and running quickly.
Choosing the game becomes more important and in some ways easier. You only have two people to talk it over with, so you can choose a game that you both really love and that fits one-on-one play.
I have found this kind of play really rewarding. It almost feels like we get a year's worth of gaming done in a month's worth of sessions.
My biggest worry and adaptation is that I scale back the NPCs and hirelings. I don't want them to overshadow my solo player. I ask a lot of questions, I'll give feedback more on decisions and in general, I try to fill the "party" role of being an advisor/sounding board without taking over the game. It's tough.
I find that my biggest problem in a 1-on-1 is maintaining my interest, followed closely by having something resembling a plot. I tend to run "sandbox" style, and cue off my players. My most comfortable group size as a GM is 5-7 players; 2-3 is not easy.
My coping method is to use moderately abstracted systems (GW Judge Dredd, Pendragon, Burning Wheel, DL5A, Saga Marvel or Advanced Marvel), and in media res setups, and most of those have great random stuff tables or systems. I also make use of all the random tools provided (59D Search charts for JD, random holding events in Pendragon, random card flips for inspiration in DL5A or Saga Marvel, the random crime charts in MSH) to provide hooks for both myself and the player to grasp on to.
Burning Wheel is actually quite easy to sandbox for one player, tho'; it's so player focused already, and the use of beliefs, instincts and traits points you to where the player wants you to hit his/her character, that you can much more easily keep momentum up.
More often, however, I just break out the board games when I'm down to one player.
When DMing for one person, I do take a pretty different approach. There's no worry of keeping loot balanced for the entire party, it's a lot easier to tailor the story specifically to the single player, and perhaps use (or abuse) elements of their background. It's very easy to bring up repercussions for their previous actions because you don't have to be worried about disturbing the entire party cause one person lets their roguish tendencies get the better of them. It is a lot more personal, but it can lead to some more involved stories then trying to sandbox play a party of five in my experience.
When I run a personal game, it's heavily dependent on who the player is. In most cases, I can only find time to roleplay with one particular friend and he's not the best with puzzles or hints, so, in tailoring games for him, I look to video games for plot lines, things he'll sink his teeth into right away. For other friends, I try to make them investigate more, learn more about the world I have envisioned for them to explore. Since it's only a single player, it works a lot like Oblivion or other RPGs where they can create whatever story they want in the long run.
