Driving slowly so that the needle on your car's tachometer is pointing to the one--or your engine is only doing about 1,000 revs or less. This is usually done in front of a club or party in order to floss your ride and/or stereo system.
Did you see Skip's new whip?
Yeah, he came by the front of the club rollin' on the one so everybody could peep it.
Failing at a task or fumbling a job/task/situation; usually something simple. Based on the twenty-sided dice system used in games such as D&D, in which rolling a one usually constitutes an automatic failure (called a "fumble").
When he was unable to repeat what his Professor had lectured at him, James made a claimed of rolling a one on his "Listen Check".