An interesting but potentially worrisome thing is happening in my L5R game. The PCs are still working together, but as the plot goes on and as they're taking mental blows from the plots of their opponents, the group is starting to fracture inside. The crux of much of what is developing into conflict is differences of opinion on how to handle core things. With it happening in my game, I figured it might be a good time to talk about Intra Party Conflict, and how to handle it.
The IC vs. OOC Divide Is Key
For those who don't know, IC stands for "In Character" while OOC stands for "Out Of Character." In other words, IC knowledge is stuff your character knows/does, while OOC is the stuff that you, the player, know but your character doesn't. For example, a long standing D&D player may know that Trolls are vulnerable to fire, but their character might not. Alternatively, you as the player may know that the party rogue is hiding a stolen artifact, but your character doesn't.
When it comes to party conflict this divide needs to be there. Players get invested in their character. Sometimes, in the moment, they don't react with a level head. Because of this, intra party conflict has the possibility of destroying games and ruining friendships if the conflict spreads from purely being IC to having OOC components.
Warning signs for this come in several ways. Players, when talking about the issue, will use player names instead of character names. Instead of hearing "Man, Gramgor should not have sent the army to wipe out that village" you hear "Man, Sarah should not have sent the army to wipe out that village." The other signs though, aren't quite as clear - especially if you don't have regular access to all your players. The players will be more irate with each other, or short with each other.
So how do you fight it? The only thing you can do is talk to your players. Talk to them as a group and talk to them as individuals in private. Make sure everyone is cool with the conflict going on. Make sure people understand it's just IC and that it is for the story. If someone says that it might be spreading, or that it is harder for them because of some other OOC thing...you need to kill the conflict and fast. No matter how good the story in your game is, it's not worth the game's life or the friendship between your players.
It Should Never Be Forced
Trust is a fragile thing and this is true for both characters and players. Because of this, you don't want to force intra party conflict into the game. By this I mean don't give two characters in a long term game directly conflicting goals without speaking to them - and the group - first. It is one things for a player to decide their character is going to do something, and that thing being against the wishes of the group. It is a totally different thing for the GM to force a player into that position.
Besides, the best conflict is going to be the kind that the players opt into themselves. Why? Because it means it is going to flow naturally from the player into the character and then into the game. Give the opportunity for it to happen, but never force it to life - unless that is what your group wants.
You Might Be Better Off Without It
Frankly, not every group is going to work with intra party conflict being a thing. Some games are going to be a lot better without it. Some stories will hinge on there being no reason for it to happen. More to the point, some groups just can't handle it.
If you have any players in your game where the idea of losing their character, or being denied a key plot point or thing, makes them particularly upset or sends them into a rage or depression...you really don't want intra party conflict in your game. Why? Because everytime players butt heads, one of them is going to lose...and player characters seldom but heads over things that don't matter.
To be perfectly honest, for the vast majority of my GM career I flat out didn't allow intra party conflict. I later on, when I found a group I thought I could trust, loosened up to allowing intra party violence - in specific situations - but only with very strong and clear cut in character motivation. It's only now with my current group that I find myself trusting the players to really let it be allowed.
Everyone in my group likes the same kind of game. We tell stories with our characters. We accept that loss is important. We understand that sometimes shit happens and you lose or you die. Because of that I'm letting it happen. But even in the groups I like playing with and do play with right now, swap out any player for another and I'd be back to not allowing it until I knew the mesh was there.
Intra party conflict can add a whole lot to your game and bring in dimensions you never thought possible. It can also crush your game and leave it broken in its wake. Take it seriously. Tackle it openly with your players. Make sure that what happens at the table stays at the table. Otherwise, you're going to get burned, and badly at that.