But there’s a nuance for “all bets are off.” It comes from craps and is not literally referring to “all” bets.

Most folks know that craps has the Pass/Don’t Pass bet, which is whether or not the roller will either win on the first roll with 7 or 11, or make the number he is rolling for before losing with a 7 roll. This bet is placed before the first roll and so is a purely speculative bet. This bet cannot ever be withdrawn.

But, once the roll is made, and assuming it is not an automatic win or loss, then before each subsequent roll you can place “side” bets. For example, that a six and/or eight will show up before the roller wins or loses.

These side bets remain on the table until the person who placed them decides, before another roll, that he wants to withdraw them. If he has multiple side bets and decides he wants to withdraw all of them, he just says “all bets are off” and all the side bet chips he placed are returned.
Any Pass/Don’t Pass bets he made remain.