Zombra wrote:...or battle each other to save/kill the mayor and so forth.
In this particular scenario I was thinking that the option would be there in the single player game, to choose either side, and face an enemy force; but that if the other player happened to choose the other side, that their rangers would be that enemy force; and make that quest noticeably [and unexpectedly] more challenging to both.
(And preferably with more than two outcomes.)
As an aside: There were two other examples I recall from FO3 speculation back then, one was interconnected factions, like each NPC could be of the town
faction, but some could also be of the smuggler
faction; and as such, even friends of the party might change behavior when the party treads on faction interests... IE. A farmer asks them to clear his fields of varmints, and later asks them to repair his barn... even lets them stay in the barn, but when they discover a smugglers den under it ~that's when he burns it down with them in it.
The other example was that the party sets out to clear a bandit cave, and the player uses stealth to infiltrate the cave, and fill it antipersonnel mines while the bandits are out on a raid... Effectively ending the bandit problem; but the player did not clear the cave of the many mines that were placed, and so the next time they pass through the nearby town, there is a funeral in progress for residents that explored the bandit cave.... perhaps even with the sheriff asking them to clear the cave of mines, and investigate into who might have set them.