This may be one of the more controversial pieces on this blog, but I have a theory. Maybe it is more of a philosophy? Anyhow, my theory/philosophy is that in any game there is a certain amount of special. That amount is a constant. It doesn't increase. It doesn't decrease. It is also evenly, or unevenly depending on the game, divided amongst the PCs. Today I want to talk about what that means, and how it can help you as a GM when handling larger games.
What Do You Mean Special?
Before I can talk about how to manage the amount of special we need to know what being special means. By special I mean how much the world will flex for them. In other words, how much of a "protagonist" they are. How likely Kings and other special people are to recognize them. How much bend the world will give in chance, favor, and coincidence. Essentially, how much the world revolves around them.
Think of it like the movie. The main character's life is full of coincidences that help them out - or put them in trouble - because the world revolves around them. The story revolves around them. In your game, the story should also revolve around the main characters - they should be the main characters after all - but how much should it revolve around each character?
1 = 100%, 2 = 50%, 4 = 25%....
The movie metaphor goes further with this. Consider a movie with a single protagonist. Look how much they accomplish, how they rate compare to other people, and how much happens to keep things about them. In a movie with a single protagonist the movie's plot is often personal - even when it is also grandiose. Add a second character and suddenly things are still important for the two characters, but not as much is around one or the other. This trend continues as the number of characters goes up.
Now, movies don't always do even splits. Ensemble Casts are wonderful, but the story tends to focus around a core group. The Oceans 11 series focuses around Clooney, Pitt, and Damon. They are the characters who get the majority of focus, and then the others get what is left to do their jobs. Suicide Squad focuses on Deadshot, Harley Quinn, and Flagg (I think that's his name.) In a movie this works because it gives the audience people to focus on, while the other characters can be used for random jokes, to be killed for tone setting, or any number of other reasons.
In a game you can't do this. Well, maybe you can - and maybe it will happen anyhow - but it is harder to focus on just a few players because the audience are the players and if you're only worried about 2-3 of the players, the others are going to be super bored and that's not good. So, what do you do?
Less Players, More Special
The less players you have the more you can cater to them as individuals. That means more personal connections, more personal plots, and the more their characters as individuals are directly relevant to what is going on in the game. You can safely entwine key elements of the plot and relationships with antagonists and other characters.
Doing this comes with a risk. If a player character dies it can kill off a portion of the game. However, you also have more leeway and room to have elements come in that protect against that type of character death.
Either way, the point is, the less players you have the more room you have to fit the narrative into those characters.
More Players, Less Special
On the other hand, when you have more players there is less and less time to explore the depths of those characters. Stories become more about the events. The PCs are still special, but as individuals they are not as much. PC Fatality means less in this game, and the more players you have the more likely it is that someone is going to catch an unlucky day in combat and that'll be the end of them.
This doesn't mean personal touches can't happen. You can work things in, and some GMs are amazing at weaving personal backstories into games regardless of how many PCs are at the table. In general though, the pull any one character will have in the world is reduced, and the protection they get from being a PC is also reduced.
Games don't tend to work like ensemble films. Or maybe it's more that they do, but there are no main characters. That means anyone can die, and the game is expected to continue on.
There are two big caveats to this.
First, there are some games that make a point that the PCs aren't special. They're still the main characters, but by virtue of PCs they're not better than anyone else in the world. These systems are often very gritty (Shadowrun and Shadows of Esteren are two examples) and in them even in small groups, by design, anyone could end up dying just from a bad day of dice.
Second, in sandbox games that go a very long time you can work in a lot more personal plots over a period of time. Often this means the game has to go more years than months, but that also depends on table size. Effectively, people get turns as things relating to their characters comes up, is resolved, and moves along. It could be as simple as one session a mentor from a character's past shows up for a bit, or it could be as complex as an entire plot around one characters home clan and what is going on back there.
The Wrap Up
Take stock of your group size. You know what you can do. The more players you have, the more you want to be focused on stuff for the whole group so you can keep things moving and entertaining. Personal plots will come from this, but stories being more event driven - even sandbox games - are ok. As the number of players goes down you get more time to explore each character as an individual.
Being able to control this in your GMing is, in my opinion, the key to managing bigger groups. You just have to accept that in a bigger game people might not get their personal plots from the GM or world. They may have to just do them themselves around the events that are going on.