Y'know, sometimes it's good to push Pure Realism aside for a more interesting Roleplay experience. In my Demon: the Fallen caving adventure, there are two women who are pretty opposed to each other. One is a Risen Dead woman who has been trying to annihilate the Earthbound who heads the cult for several years now ever since she died trying to take down the cult with the rest of her team (who pretty much all died). The other is the Chief Handmaiden, the second-in-command to the High Priestess of that cult, who has been knocked down and de-thralled (she was only a 1 step thrall for those who know about the Earthbound) using a special artifact knife and compass combination.
Basically, the compass, when activated near a person, reveals that person's sympathetic ties. Magical connections can then be cleaved with the activated knife (which has no physical blade, by the way, just a hilt).
Long story short, the Chief Handmaiden wants to come along and finally prove herself by taking down the tyrant Earthbound that she had grown to hate and fear. The Risen won't fight in a group with her because of their past differences and a total lack of trust.
So, naturally, I thought of all kinds of terrible repercussions depending on who they chose, but then I thought to myself -- why not make things more interesting? Why not make the choice mean something a bit more complex than a simple Win or Lose scenario (or even Lose / Lose, as sometimes happens).
In videogames, you sometimes get a choice between two options, both of which have their benefits and drawbacks, and both of which change the nature of the gameplay as well as the storyline and the ending.
The Risen is an elite combatant, superstrong, and with a good skill in shotguns and a machete. Not to mention she doesn't feel pain and can take quite a few hits before going down. She's fairly brutal and direct in her actions, though.
The ex-thrall understands the remaining survivors, the lay-out, and the traps. While some of the traps and plans will have doubtless changed, she's best placed to figure out HOW they might have changed by taking a look at the signs. Of course, she's used to out-thinking the enemy and other than throwing knives, really isn't all that skilled in combat. As a regular human, she also can't take a hit effectively.
Both, obviously, have their own agenda, too, which will influence things again.
So at the start of the next session, I will offer the players a choice and that choice will be a fork in the road - not just in terms of story progression and roleplay, and certainly not as a case of right or wrong, but in terms of how the game itself is likely to play out.
Think about it. It's a fine difference, but a big one.