When pretending to be someone else, you really need to look the part. Dress properly, have the right gear, drive the right vehicle...
It does make it slightly more difficult to impersonate people higher up the social ladder. People can often drop a few social classes by acting and being a bit more scruffy, but moving up even a little is much more difficult. As a game rule, you could assess a sliding scale of penalties depending on how many levels of social class a person is trying to pretend they are above or below their own.
Commentary by memnarch (who has not seen the movie)
I don't think I'd count being "over the lameness threshold" as just a flesh wound for Chewie, so Yanni's being a bit more of a jerk than usual. Unless Chewbacca has extra Wookiee toughness that allows for faster recovery or something, I can't think of any good reasons for Yanni to try downplay the injury. Also, two minutes? That's gotta be some kind of record for identity changing right?
Maybe if Yanni grabbed some of those severed tentacles and tried disguising himself as a Kanjiklubber disguised as a rathtar, that'd be more suspicious. Oh, and talking loudly about holding a party with these three new totally-just-a-prisoner individuals; even better! Hopefully the rest of the party can talk Yanni into a more sensible course of action. Maybe one of them will say that taking a Kanjiklub ship would look more suspicious with three non-Kanjiklubbers, so they should take the Falcon first to establish a baseline. Then once everyone's on board the Falcon, they'd just need to create a distraction for Yanni so the whole mess can just be left behind until he remembers it later.
Commentary by Keybounce (who has not seen the movie)
First off: How in the heck are you going to pull off the "I look like a Kanjiklubber" if you still look like Han Solo?
Second: You clearly do hear properly. You just pronounced "Kanjiklubber" properly.
Thirdly: Oh, I'm certain you can be more suspicious. You're a player character, and you just got challenged. Of course you can reach new levels of
We saw Tasu Leech in Kanjiklub. In #1961, we briefly see Yanni. As far as I can tell, it's red uniforms vs black uniforms, and Yanni seems to be in black, so Han/Xasha is correct in calling him a Kanjiklubber. But it takes more than a name - you'd need to have a passable disguise to look like someone whose face you really did not see, and anyone that knows the real Yanni will know that you are not Yanni.
Like every member of Kanjiklub currently here.
So this plan only works if you have a total enemy party kill. Which, of course, is normal in most RPGs. But, then you have everyone else in the universe that knows what you look like.
So, these people who were looking for Umberto, or Sergio (hold on - how long ago was Sergio? Or did he skip Mr. T?) - did any of them have a picture of who they were looking for? Were there no records, no holograms, no anything of what this person they were hunting looked like?
This whole "serial identity thief" thing seems less and less believable the more and more it gets examined. It's like thinking someone could be anonymous on the modern Internet, or have a secret identity with all the security cameras, or find a telephone booth to change costumes in and not be noticed while doing so. What's next, a pair of glasses being a full disguise kit? (Hey, Superman also had a lock of hair that could conveniently move from one ID to the other.)
GM: Rey, Finn, you arrive at the hangar to see Yanni helping an injured Chewie towards the Falcon.
Finn: Xasha! Is Chewie all right?
Yanni: He’s fine, just a flesh wound. And more importantly, I’m Yanni now.
Chewbacca: Your sympathy is overwhelming.
Rey: Yanni? You were gone, what, two minutes, and you stole another identity?
Yanni: You two go look for the Kanjiklub ship. We’ll sabotage the Falcon.
BB-8: I just want to say I had nothing to do with this idea.
Finn: Why find another ship? We can just take the Falcon!
Yanni: I’m Yanni! A Kanjiklubber! It’ll look suspicious if we don’t have a Kanjiklub ship.
Chewbacca: I’m not sure anything could make you look more suspicious than you already do.
Yanni: Is that a challenge?!
Chewbacca: Oh good grief, I hope not.