The other week, Pointyman of "Life and Times of a Philippine Gamer" made a post where he pointed out that just because your life has taken a dramatic change thanks to your awakening/transformation/eruption/or whatever it is that made you a PC, doesn't mean that your life is done with you. There were a few comments made, but Pointyman's point is still a good one to keep in mind when running a game. People's lives, or at least the aspects of their life, are rarely willing to let go, even if all we want at the moment is for them to go away. So, let's take a look at what goes into bringing the aspects of everyday life into your game.
Now, I'm not going to go over the specific things that can come up for the PCs. Pointyman did a good job pointing out some of the obvious things for one, and, well, they'd be different for every PC anyhow so there really isn't much point in trying to handle the specifics. Secondly, a lot of the advice in this post is going to be hard to apply to a game like D&D, L5R, or other non-modern day setting games. Those fantasy and sci-fi games often have things built into the setting to let the PC off scot free. Especially when they're soldiers, or professional adventurers. Modern games aren't like this though, and really, in most stories told with a modern setting the separation from your normal life is a big aspect of the story.
As I said, I'm not going to go into specific examples of parts of someone's life that can come back to haunt them. Luckily, the basics aren't hard to understand for this, and the basics are all you really need too. So, take a look at the PCs in your game. For one, how old are they. Are they teenagers or younger? Grown adults? Middle aged? What is their life like, before whatever happens to make them special happens. Did they go to school? Have a job? A wife? Girlfriend? Kids? Were they a member of any team, club, or group? Those are the things that are going to come back to haunt them. Those are the things that will show up, find out what is going on, and want to know why the person is breaking ties and backing off. So, after a few sessions go by with all the PCs just hanging around, and running amok with their new found powers and abilities, have some aspect show up. A phone call, an angry parent demanding to know where they've been, a neglected significant other. Something, just bring it up.
Like I said, the basics are fairly self explanatory, but you have to be careful here too. The two things you need to be careful of are overdoing it, and controlling time in the spot light.
Overdoing it is the big risk here, especially at the start. Sometimes people are playing in an RPG to escape the hassles of real life. They don't want to be harassed by their career, or whatever other little mundanities happen to be in their real life. This person, probably doesn't want their escape to be dominated with their character being harassed by those exact same things. This doesn't mean you can't do it, hell, a little bit may even go over well, but when it becomes the focus for the session you have a problem. In a lot of ways, these 'everyday' hassles are like spices when you're cooking. A little can be great, adding just a touch of the right flavor to bring out the best in a game. Too much though, and you can ruin the whole experience.
Now, I know what you're thinking. Especially if you're thinking of that analogy. Some people like more spices than others in their food. So how do you tell? Well, just watch them. Bring up something, and watch how they react. Do they 'handle it' and move on? Or do they react to it and try to make it a part of their character's life? Odds are, the first person just wants it to be a dash here, a sprinkle there, while the second person wants a bit larger of a helping in their game experience. Obviously, in this case, serve appropriately and let them enjoy the meal.
Now, spotlight control is another issue that has to be handled here. By definition a character's personal life is personal. That means that it is unlikely that scenes involving a character's life coming to harass them is going to involve other PCs. Which, in short order, means that you are splitting up all the PCs into their own little things. When that happens, you need to have a good grasp of time and when to shift things over. I used to be better at it, and it is something I am trying to get better at working with again, but it is an important skill as a GM. You want to be able to shift from scene from scene quickly. Try not to be with someone for more than 10 minutes if you can avoid it, 5 minutes if you have more than 4-5 players in your group. This keeps everyone involved, which is a whole lot better than 1 person having fun, and everyone else being bored.
Bringing people's everyday lives into games can be a tricky, but fun thing to do. It can really help add that element that a character is a real person, and when your players invest in that, you can see all sorts of fun changes come about in how the player plays them. Just be careful not to force it on people, if it isn't making things more fun for someone, don't keep bashing them over the head with it. Eventually, with the right amount of effort, you can kill ties with just about anything, and even the most clingy of family members will eventually give you your space for a while. So, let the player do that if they want the full escape.
As with everything, have fun with it, and let me know about any experiences you have with pulling this off in your own games.