I'm running a Starfinder game, and we are 40 sessions into this campaign.
The campaign involves the fate of a small but strategically important settlement, which several factions are vying for control of. My group are from several different factions, but have temporarily agreed to set aside their differences to fight the largest threat. The keyword here is "temporary".
The thing is, 40 sessions in, the scenarios the group finds themselves in have forced cracks into this temporary ceasefire, as displayed in what happened last session:
The mission in question
The group found themselves contacting one of the factions (Alignment Neutral Evil) that PC number 1 aligns with, on the behest of PC 1. PCs number 2 to 5 are mostly following along for the ride. They find some fairly uncomfortable information with what this faction intends to do with the PC's Settlement.
PC 1 reacts with excitement. PCs 2 to 5 are less enthusiastic and are put in a bad mood.
Later in conversation, some NPCs (who the party was informed, is extremely hotheaded) aligned with the aforementioned faction provoke the party in a "bar fight" scenario. PCs 2 to 5 defend themselves, while PC 1 rolls diplomacy rolls to calm the NPCs down, and administers medical aid to the NPCs after disengaging.
This forces the party to determine a method of leaving undetected, which they did by causing a distraction elsewhere with a riot in the internment area, much to the dismay of PC 1. During this, two of the prisoners agree to help the PCs leave the facility. PCs 2 to 5 eventually warm up to the two prisoners.
The PCs were eventually busted. PC 1 abandons the group to their fate and dashes off, with PCs 2 to 5 and allied NPCs making some clutch stealth and athletic rolls to bumrush off. One thing that concerned me at this point was that Player 1 (not PC 1, Player 1) spent some effort requesting I provide PCs 2 to 5 with harsher disadvantages that the ones I already provided them based on circumstance.
After escaping to safety, one of the NPCs expressed his gratefulness to the group, and stated that his employers (another faction whom the group does not like) will like this, and provide payment. Upon this, PC 1 shot him, and due to the high damage roll, PCs 2 to 5 could not react in time to prevent this.
This has caused a rift between the PCs, and PC 1 have both openly requested to kick a member of the party, as well as openly plot to murder the surviving NPC, who is aligned with a faction that the group currently works with, but PC 1 absolutely hates.
Attempted solutions
We had a Session Zero when we started, stating our intentions with in-party conflict. Our conclusion was "avoid PvP", but we left it there.
For the last 40 sessions, I have given them various reasons to stick together, i. e. the BBEG. However, with the BBEG's forces weakened, these factional issues resurface.
I did not do a group character creation session because I did not imagine the PC conflicts would get this severe.
Additional information
- This is Player 1's first campaign. I (and another player) have spent the last year attempting to teach him the ropes of TTRPGs throughout this time. His character backstory was changed around Session 11 and Session 28 to integrate his faction (which was originally a throwaway faction set up in Session 7 that I have better developed due to Player 1's interest, something the group seemed to respond well to at the time). This is part of why I don't want to expel him from the group.
- Players 2 to 5 are experienced players, and GM in their own time. I have explicitly requested them to try to work with PC 1 for as long as possible.
- This is my first GMed campaign, and I did not expect the campaign to last this long. It was supposed to last around 15 sessions with factionalism being a more limited factor, but the players requested I continue due to a continued interest. This is around the time that Player 1 changed his backstory to better integrate his faction . Judging by Dragomok's well-received answer, this is where this issue might have started.
- The players have stated that they wish to continue playing, and seem not to be particularly distressed by this event. However, if things get too severe, I will leave it to the PCs.
Please let me know if more information is required. System is Starfinder, if it helps. Tone of the campaign is action comedy.