It's irresponsible to do things without thinking about the consequences
Harper is on vacation in Las Vegas on a tight budget.
Harper wants to gamble.
Harper sets a gambling budget so that she doesn't overspend.
Harper plays a game of poker and bets everything in her pocket.
Harper loses a game of poker but is still able to enjoy the rest of her vacation due to her budgeting.
Harper loses everything she has and can't afford to do anything else for the remainder of her vacation.