I am sure that more than one has been in the same situation and has the issue under control but I have been asked about the topic a couple of times. And now that it seems that I am going back to DMing one-vs-one after some time, I have found myself thinking again about it. So I am going to throw some of the issues I think are the most important to take on DMing with just one player.
You need to adapt the system
At least if you are gonna play a game more action-focused, as I think the vast majority are. You will have to move some things to make the difficulty just right for on character, as many games are focused on 3-5 people collaborating.
This can also mean that you will have to present less challenges focused on character ability (that is, what is on the character sheet) and more on player ability.
Also, if you can choose, it would be best to use a system that doesn't force the characters to specialize by default so the PC can stay a Jack of all trades or where they can respec the character to face different challenges. Yeah, like in many computer RPGs.
Watch out for companions
An obvious way to solve the system problem could be allowing the PC to be joined by an NPC gang that rise their numbers. This is generally a good idea and I recommend standard groups to look for hirelings, but with just one player it can have a couple of troubles.
- You just forget about them. This is normal in any dynamic, but here there are even less people to remember about those two mercenaries that stayed on guard two days ago.
- Depending on their capabilities, it is much easier for NPC to eclipse the player, so you have to make sure that they stay as secondary characters as much as possible.
You have to make more clarifications and reminders
Being just two people at the table, it is much easier that anything you tell the player won't be noticed as there is only one brain listening. If there are more players, it is normal and beneficial that they will explain things to each other and support you stablishing the situation, thus reducing mistakes due to misunderstandings or things that were just forgotten. Because, by the same token, it is just one brain remembering everything. To avoid this, you need to make a greater effort to make everything clear and do even more recap than usual.
It requires more attention and have less downtime
Ironically, a player frequently requires more attention than four because, well, you are all alone. During a normal game, you usually can catch your breath while the players are talking and making plans, but here you are either talking among you or the player is thinking what to do silently (or discussing it with you, as we will see below), so it can be much more demanding. In this dynamic I think it is more important to take the initiative to stop the game for a moment while you yourself figure out what the heck is happening.
Allow situations where you can participate
Usually fun in RPGs comes from discussing with your companions what to do next, calibrating situations and taking into account pros and cons of a possible plan. Here this doesn't happen because, well, the player is alone. But one of the possible solutions to this is that you can also be involved in resolving problems and discuss with the player what to do. It may seem like cheating that the DM, that has much more information, influences the player discussing the situations with him instead of just sticking to its role of providing information, but there is a type of setup where this can work very well.
The best approach is creating situations where there is the least ammount of hidden information possible (that is, that the DM reveal everything or almost everything to the player, so they know almost the same), there is an open solution and it depends a lot on dice rolls. For example, the prototype of the moat with crocodiles:
- There is no hidden information: there is nothing but a moat with crocodiles, with a chest at the other site.
- There are many possible solutions: killing the crocodiles, levitation over it, jumping with a pole, dealing with the crocodiles...
- The result of almost all actions that can be taking depends on the dice. Even dealing with the crocodiles should require a reaction roll or persuasion.
Games tend to be a lot quicker
Of course, with just one player, you can get ready to play sooner and, as there is less downtime, games tend to be more efficient and you can fit more content. That's great. The other side of the coin is that you have to be careful and prepare some more material than what you might usually prep for a bigger group or you might fall short!
And that is all for now. I hope you will find it useful and thank you for reading. Valmar Cerenor!