Regardless of whether you "flub your lines" or speak as if you are an Academy Award winner, the most important thing to remember is that the words should come from the heart.
If you flub a line, you have to sit out a turn.
QueenWords - You know a site named QueenWords can't afford to flub a line, and they don't!
Rehearsal footage is shown as well as the many flub of lines among other things by the actors.