Pot luck
Definition 1 of 2
Pro Tip 1/3Chance Outcome
Refers to unpredictability in a situation with various possible results. 
We didn't have a guide for the city, so we took pot luck with our sightseeing.
Pro Tip 2/3No Guarantee
Highlights the absence of certainty in what you will get. 
The bargain bin at the store is pot luck; there are no refunds.
Pro Tip 3/3Not Planned
Used when actions are taken without a set plan or expectations. 
We didn't book a hotel, preferring pot luck to find a place at the last minute.