Defeat DOES have consequences! On the public version, its only in act 1, so I'm assuming you've never lost during act 1. Typically it gives you a negative perk, or adds a curse to your deck, or forces equipment on you
Yes, my bad dont lose in 1 act LOL. The sad thing is that after a defeat, for example, certain opponents could also impose it, but this would lead to unique events/ dialogues / etc. in the following acts