Meaning
What does One and done mean?
One and done may be used as a general slang for completing something once, then you never do it again, for example a one-night-stand, or winning the first round of a competition then losing everything that comes thereafter.
However, during the 21st century, “one and done” has been associated with basketball.
To play in the NBA, the recruits must have reached 19 years of age. Because many finish high school when they are only 18, they proceed to do one year of college basketball, for then to quit and go to the NBA.
The one year of college basketball is their “one and done”.
Origin
What's the origin of One and done?
In 2006, the NBA (National Basketball Association) introduced a controversial new rule that new recruits must be minimum 19 years old.
Rather than leaving out a year of playing, the high school graduates would apply for college – knowing very well that they do not plan on completing it – then leave after the first year.
Spread & Usage
How did One and done spread?
A movie with the title “One and Done” was released in 2016, and tells the story of Australian basketball player Ben Simmons’ journey all the way from high school till he was the number one chosen in the NBA draft.
However, as the expression is simple and catchy, it can frequently be used in non-sport contexts as well.

External resources
- Urban Dictionary – One and Done