There's no need for medieval or fantasy warfare if you're willing to compromise on things you don't care that much about. So tell people why you don't like an idea at the start of negotiations.
Negotiations: It doesn’t have to be all Game of Thrones
Deciding which ideas are worth negotiating with your partner(s) in organising
I got an article request for tips on compromising wedding stuff with your partner. Negotiation works for weddings; I got my practice in while organising conventions.
Skipping Convention 