I did not see a relationship hit from doing this - though the dethroned leader gets a +2 Sad moodlet for a time, while the new leader is confident. The better your friendship with them, the more likely it is to succeed. In order to take over as leader of another club, you've got to convince the leader to step down. You'd have to convince someone to quit, which again likely requires you to be at least acquaintances with that Sim. If a group is full (max 6-8 depending on Perks), no luck.

Granted, I haven't had time to try applying dozens of times, but the higher the bar the more likely it seems to be to succeed. I think it's rather easy, as I haven't had a Sim fail just yet. If it fails, schmooze them up a bit more and give it another try. Having decent Charisma will make it very easy to get the bar to around 20% friendship, where it seems it's quite simple to be accepted when you ask to join. It's best to catch members at nightclubs or other venues where you'd expect that type of Sim to hang out. If you, for example, try to get into the Paragons and cannot get into their hideout nor get Sims to come outside to talk to you, you may be out of luck for the moment. Taking over as leader means convincing the leader to step down. Joining an Invite-only club means befriending a member, who you can ask to invite your Sim. Any of the members can accept your application into the group, so you only really need to get one to vouch for you. This can be a bit difficult if they have their own secret hideout, and in fact may make it impossible to make the social impression and chat up the members in order to apply. The group will have you over on a gathering when you click to apply. Though many of these are simple, you wouldn't want to be mean to a Renegade if you're trying to be accepted to that group. For invite-only clubs, make note of a club's rules first and foremost.

If a club is open invitation, you're in - that's it - just go to the club list and click Join. This is repeated elsewhere, but if you found this page wanting to take over as the leader of the Paragons, Renegades, or any other club, you can get the info here: Still, it may be desirable to attempt to take over the prestigious invite-only clubs, the Avant Gardes, Renegades, and Paragons. The Sims 4 Get Together Expansion List of Existing Clubs, Join Requirements, and Activities There are 11 clubs to join in the Expansion, but you can make your own.

Sims 4 club mods