In most RPGs, there is virtually no interaction between the various characters outside of the main story or sidequests. I honestly find this a pity, especially when it involves players trekking through deep dungeons. It feels unrealistic for individuals to not engage in at least some sort of banter every once in a while, especially in reaction to recent in-game events.
However, one series has taken this into account: Namco’s Tales series. This action-RPG series has had, for a while now, a “skit” system. Every so often (usually after a story event that has just transpired), a button prompt will appear in one of the corners of the screen with the title of the skit.
Pressing the button will treat the player to a scene where portraits of two or more characters (just one on rare occasions) will engage in discussion on said events, or may seem completely unrelated to the events that just transpired. Of course, this is not the only reason a skit will occur. They will sometimes pop up when:
Of course, these skits wouldn’t be nearly as interesting if the portraits did not changed to reflect appropriate expressions, and in later entries in the series, actual voice acting. Furthermore, the portraits also manage to exhibit body language of their own, such as bobbing up and down when laughing heartily, or zipping off-screen when trying to flee, or suddenly forcing itself in between other characters trying to have a conversation.
Being that non-verbal communication is considered to be the majority of what we have to say, these seemingly minor additions make skits far more compelling and interesting to watch. But of course, these skits have a greater purpose. They are enhancements to the story, and to character development. These skits give other characters a chance to shine, to give us a peek into their heads, and perhaps to just watch them goof around, adding a touch of lightheartedness to an otherwise serious situation.
So, how could other games benefit by the addition of a similar system? For the same reason it helps the Tales series: it gives the writers an opportunity to explore new facets of the characters, and serves as further meaningful story without taking up too much hard-drive space, and finally, it makes the group of allies feel much more like real people. While many RPGs may use something like this to determine the relationship the main character will have with his or her fellows (which in turn affects part of the story), this can fit in other games.
Imagine, in a military shooter, the opportunity for the player to interact with AI companions in between missions. It would be a glorious opportunity for writers to build on otherwise completely shallow characters without cutting too much into game time. To encourage players to view these skits (which will most likely NOT follow the method uses in the Tales of games) they could give some minor benefit, such as a squad mate having a greater tendency to come to your aid, or they may even give the playable character an item to be used in the next mission. But even with these benefits, a designer must take care to ensure that these skits act primarily as story enhancements, and do not drastically affect game balance.
If done right, skits (or variations thereof) are a marvelous way to develop otherwise shallow characters without depending too much on exposition in the main story.