This really gets my goat...

[hayduke]

I am playing 7 Wonders Duel more and more lately... using both expansions.

It's tiring when people sit down but then leave immediately after seeing it's both expansions.

OR WORSE when the game starts and I get the, "Oh I don't know how to play with the expansions."

Read the tabe options before you sit down or hit start, FOR ALL THAT IS HOLY!

[nmego]

I'd assume some of that is due to the auto match-making feature.

[voriki]

I feel the same way with Love Letter 5+ players.
When playing with 3-4 players, you play with the basic 16 cards: 5 guards, 2 priests, 2 barons, 2 handmaidens, 2 princes, 1 king, 1 countess, 1 princess.

But as soon as you are with 5-8 players, it adds extra cards, with new functions and causes a whole other gameplay: 1 jester, 1 assassin, 3 extra guards, 2 cardinals, 2 baronesses, 2 sycophants, 2 counts, 1 constable, 1 dowager queen, 1 bishop

And then they act surprised, start attacking people who've played a constable, attack their temporary alliance member who've jestered them, sycophant the next player in turn, etc... classic newb moves.