About halfway through a 6 player game of Euphoria, I announced a rule I had forgotten to tell everyone at the beginning of the game: you can trade artifacts, commodities, and resources. Everyone collectively yelled and screamed and swore that would be the reason they each lost the game. I grinned, a bit sheepishly at first, but genuinely amused by everyone’s claims. I assured everyone that trading was rare and I couldn’t even remember anyone ever doing it in previous games. Of course, everyone made a bunch of trades and, in fact, the winning star placement was made possible by a trade.
I don’t care that I never manage to win this game, I love the experience it offers.