I think by now I can safely assume you all know I love the groups I play with. However, even with how "high level" I boast, we aren't above doing stupid, standard PC bullcrap. This is especially true when it comes to how we roll through town in games. Like most player groups, the event could really only be described as "on par with a biblical natural disaster." You know how it goes; three months in and your campaign map tracks the PCs' progress by which cities are destroyed and which have yet to even be visible on the horizon line. The kind of PC actions where "you're not giving me a deal, so I'm just going to burn down the city block" seems like logical and rational planning.
Yeah, I'm exaggerating here - a lot - but you get the idea.
So we're prone to that. However, in one of the games I'm in right now that isn't happening. It isn't happening so much that a PC (mine, to be honest) has actually spent two nights talking themselves out of murdering someone doing things they didn't like and thought were unforgivable. So much so that a PC is trying to work with the entrenched leadership in the local town to get what we feel we need to "win" rather than just kill/replace them. That a PC is suffering insults against their honor in order to keep good working relationships. That a PC has actually put thought into the political ramifications of who they're spending time with. That two PCs stealing a holy stone from a church is still a secret they can't share or laugh about for fear of word getting out.
All in all, most of the social constraints you see in stories but never in game are present and functional. And I think a big part of the why for that is one simple thing: the game can't leave the area.
Now to be clear, nothing says all the PCs couldn't decide we're leaving and go somewhere else. THe GM would go along with it too. However, it's unlikely our characters would all go the same direction without extreme pressure or an army, so that would in a sense kind of break the game.
No, all of us want to stay in the town (on both an IC and OOC level) and that means something that isn't always true even in high level, heavy story driven games: we can't escape the consequences of our actions by leaving the area.
Let it sink in for a minute. I mean, sure, my PC could just go out and murder the one or two people on their hit list. But what happens then? The game isn't leaving the town, so now there is the fallout of the murder. Those people have allies, friends, and loved ones (well, one of them may not have the last two...) and those allies/friends/loved ones will want justice. Not to mention the real story in the game has the PCs needing the town to pull together, and that is a lot harder with a murderer on the loose. Even if steps were taken to get away with the kill clean, there are consequences, and as long as we're in the area - and we're not leaving the area - the threat looms overhead.
For much the same reason the PCs have to play nice with entrenched leadership. Sure, we could rock the boat and spill everything. But then what? Resources and people that are needed could be denied. What are we going to do? Kill the whole town to get the resources needed to save the town? What happens when NONE of the NPCs will talk to us?
This is also one of the reasons that PCs are always nicer to other PCs. Even if you can escape the IC consequences, the OOC consequences are there. And an action with consequences that can't be escaped is a much bigger deal than one without that threat.
It's an interesting experience. It's a fun experience too. See what happens with your own play groups when they can't just leave the area once their job/mission is over. Or better yet, let them think they'll never be coming by the place again...and then send them back, this time needing help. You might be surprised at what you see happening.