We often talk about how to avoid downtime during a game session, but we don’t really talk about downtime before the game starts. By this I mean the time when some of your players show up, but the group inevitably ends up waiting for that last player. You know he’s on his way, but you know he’s also running late. Whatever the reason, maybe he has a lot further to drive or he gets out of work/class later than the rest of your players, you will have time before the game actually starts and you have players sitting around.
Unfortunately, you can’t start the game until he shows up. Perhaps you are in the middle of an encounter and his character is needed. Perhaps the group has reached a point where they need to make a major decision, as a group. There can be a number of reasons why you can not start the game until the last person arrives.
The normal response is to sit and talk, get all the socializing out of the way before the game begins. This is not a bad idea, but if you tend to be cramped for playtime (with my group we schedule 3 hours of playtime so any time taken away from that diminishes the game) looking for ways to utilize this downtime can only help.
There are a number of things you can try to do. The key is to try and do things that are relevant on some level with the game you will be running that night. Also, whatever you do has to be flexible enough to allow for those who do show up without alienating those who do not.
Here are some ideas I’ve used in the past...
Back when I was running 2E Dark Sun we used the Complete Gladiators Handbook to set up and run a gladiator style mini-campaign. Basically each player bought and sold gladiators, keeping up with the expenses thus accrued. They would then enter their chosen gladiator into the arena and their fortunes would rise or fall according to how well their gladiators did. The fights were fast enough that we could run one or two fights before the person we were waiting for showed up.
Flashbacks are also something that can be done. Pick one or two of the characters from those that are waiting. Write up a quick scene that doesn’t even have to involve a combat. These scenes should focus on something in their past, but doesn’t have to be something that has to do with the adventure being run that night for the entire group. For example, if a couple of the characters share a history you could revisit such a time, perhaps as youngsters they skipped school and almost got caught. Did they run and hide, or did they let themselves get caught? These sorts of flashbacks can be used to further develop characters.
Another thing you can do, which can tie into what you have planned for your evening’s adventure, is have the players run NPCs that work for the villain of the night. These can be NPCs that the players might be facing that night, further into your campaign or NPCs they may never meet. For example, I had one of my players had to leave the campaign I was running because she went back to night school and couldn’t make my game anymore. We never did a closure scene wherein she left the party. One day she was there and the next she wasn’t and the rest of the party didn’t seem to notice. I decided to play off that and had her kidnapped by the major bad guy of the plot. He then had memory of her erased. So one night, I had the players quickly generate some evil characters. She had escaped from the major bad guys control and the major bad guy gave these newly created NPCs the task to recapture her. It didn’t take long, but it gave those who shown up early for the game something to do and it tied neatly into the overall campaign. In addition, the players are now looking forward to meeting this group of NPCs. As a side note, they enjoyed playing evil characters and exploring a class they hadn’t had a chance to play yet, but had piqued their interest in the past.
Similar to this is the concept of running something that is happening elsewhere in your game world. Is there a war going on between two nearby kingdoms? Run a little war game session while you wait. It doesn't even have to be relevant to the plot or adventure. If nothing else, it adds background to your campaign world and the players will find it cool when their characters start hearing how the war is faring.
Another idea is to run a quick dream sequence. This would be about something related to the ongoing plot and should present the characters involved with some choices. Perhaps they could see what the world would be like if the big bad guy succeeded in his evil plans. Or perhaps they can see what life is like now for the child they rescued four game sessions ago. Because it is a dream, you can go a little farther with your ideas.
So, if the time you have on game night is limited and precious to you and your players, don’t waste the time you do have while waiting for that late-comer. Run your game before the game starts.