In the United States, turning 18 years old is a big deal.

For the first time, you’re considered to be an adult, at least officially by law.

It’s also usually a year of transformation. Most 18 year olds graduate high school and either begin their freshman year of college or begin their career.

Right now, 18 year olds who happen to excel at basketball don’t have the second option. Due to league rules, high schoolers cannot declare for the NBA Draft. Instead, they need to have a gap year and either play a one-and-done season in college, go overseas and make money but risk obscurity or simply take a year off to train.

But, that may change sooner rather than later.

Fighters against the so-called “one-and-done rule" will be happy.

A (possible) new era

“The NBA on Friday sent teams a memo indicating that eligibility rules’ for the draft may shift as early as 2021 (but no earlier) as the league reviews issues "related to player development and the corruption investigation in college basketball," according to Zach Lowe of ESPN.

He added, “The memo does not mention the one-and-done rule by name, but it is meant to remind teams that the league and the players union could agree to scrap one-and-done before the expiration of the current collective bargaining deal in 2024 -- and perhaps well before then, sources say. The memo says that, as of now, the league does not expect changes in draft eligibility rules to take place at any time 'prior to the 2021 or 2022 draft.'"

The information comes at a very important time for some NBA franchises.

If an eligibility rule changes in 2021, it could create a draft loaded with the top prospects from two consecutive high school classes. Therefore, teams should operate accordingly when it comes to trading away future first-round picks. Rather than expecting five-to-seven immediate impact players in the 2021 Draft, upwards of the top 10-to-15 players could become major values given their presumed talent level matched up with where they'd fall in the order.

"As we approach the NBA Draft on June 21," the memo says, "and the increase in trade activity that often accompanies it, please be reminded of this ongoing review and the possibility that the eligibility rules could change" between 2021 and 2024.

In other words, the No. 3 overall pick (with the current rules) in the 2021 pick might fall to the No. 7 pick (under the new rules) if the right amount of standout high schoolers are able to also enter the draft and spice things up for talent evaluators. Therefore, it will be interesting to see if teams try to include 2021 or 2022 future first-round picks in upcoming trade deals, understanding that a stacked draft could be on the way. Of course there might be an unexpected decline in talent among the two classes that would combine, but all that high-profile talent would most likely create one of the most exciting offseason NBA events in a long time.