Here's how a band of unlikely heroes defeated Vecna and save the Forgotten Realm
I've gotten mad during a board game cause I was the one being constantly attacked by someone even to their own detriment. When someone would rather I lose than them win, I will be mad at them. I've for sure made people mad, my favorite games are Cosmic Encounter and Diplomacy and board games are my Safe Space for being a deceptive little shrew. Lying is totally allowed in both games and is basically a necessity in Diplomacy. If during a Cosmic Encounter negotiation if I say ill trade my strongest attack card for your weakest, it probably means I dont have any attack cards and tricking you into agreeing to giving a card away and allowing me some defense until I can draw again.
Super long games where someone gets a runaway lead and you're just playing out the inevitable for hours gets frustrating as hell if your group doesnt do mercy rules. Sometimes you could have another game in the time it takes to reach a slow but inevitable defeat and unless theres a way to play for 2nd place or whatever it stops being fun