This topic gets brought up a few times every week, and generally the discussion ends up as "expert lobbies bad" without anyone explaining why this exists, only why people think it exists. I exclusively play Expert-tagged lobbies and I actively search for lobbies that run house rules. I have done so for going-on three years now, so I feel qualified to speak for why the Expert-lobby folks so commonly have No-Selfing as a house rule.
First of all, there is a distinction between the more common "No-Selfing" rule and the rarer "No-Imp Reporting" rule. No-Imp Reporting is the problematic one, as it bans imposter players from ever reporting bodies. As one could expect, it gets used to clear crewmates easily and is run by lobbies that don't really intend to lose as crew. If you play in a house rules lobby, treat this rules' presence as a red flag.
On the other hand, No-Selfing or No-Self Reporting generally only means imposter players cannot IMMEDIATELY report their own kills or alternatively cannot report the bodies of anyone they kill UNLESS NECCESARY (specifics may vary by host, ask for clarification before taking a chance). The reason for this rule is fourfold:
- The lingering stigma: Back in the prime days of 2020-2021, when we ALL were noobs, selfing was a common tactic. As a result, the tactic remains associated with low-level, new players, and as such is looked down on by the "experts" purely on principle.
- Interference with other Imposters: For a similar reason why nearly all house-rule lobbies run the "No Dead Imposter Sabotages" rule, experts value the control and skill of each individual imposter player vs. the skills of the crew as a collective. Anything that causes one imposter player to interfere with the gameplay of the other/others is therefore frowned upon. This includes shapeshifting into the other imposter, trying to rope the other imposter into clearing one another, snitching, sussing, etc. By self-reporting and triggering a meeting, an imposter player interferes with the gameplay of the other imposter/imposters thereby making the tactic despised.
- Control: There is truth to the fact that expert lobbies are controlling. For the same reason why the recently created Auto-Kick mod is so popular (the mod that scans the level of joining players and kicks/bans anyone below some chosen level), expert lobbies want to enforce a certain level of minimum competence on all players in the lobby. Because of reason 1, self-reporting is associated with new players, hence why it is banned on principle.
- Clarity: Credit dreamilyyy for reminding me of this. The final reason is to simply prevent the spamming of "Self" in chat whenever a body gets reported. Another consistent fact about expert lobby players is that they hate repetitive or disruptive behaviors like "start" in lobby, "random" button pressing, and door sabotage spam. This might actually be the biggest reason honestly.
Ultimately, what the house rules actually mean does depend on the host, I'd be lying if some lobbies didn't treat "No-Selfing" as "No-Imp Reporting", that does happen. But as someone who has been playing consistently in public lobbies for a long time, I stand by the value of house rules, and I understand why many high-level players want enforced competence. A balanced lobby where EVERYONE is trying, is capable of doing work, and no-one throws or leaves instantly is an incredible experience that I personally always aim to have.
But I know a lot of people just play casually and aren't really "tryharding" all the time, so I hope I was able to explain some of the enigma that expert lobbies can seem like from the outside.