The version of 3-on-3 coming to the Tokyo Olympics in three years isn’t exactly the same game seen on so many local playgrounds.

The IOC today added 3-on-3 to the Olympic program for 2020 in an effort to give the games a more youthful and urban appeal. Basketball and Olympic officials hope the half-court game is as successful as beach volleyball – a smaller, faster version of the 5-on-5 sport.

Just don’t expect it to look exactly like the recreational sport you might be used to.

After scouring the short and long versions of FIBA’s 3-on-3 rulebook, here are a few key differences between the Olympic version of the sport and the kind played in gyms and on driveways:

— THE BALL AND COURT: The court itself looks a bit different than the one at a typical playground. The FIBA court measures 15 meters by 11 meters (49.2 feet by 36 feet), with a 2-point line that measures at the same distance for the international 3-point line (6.75 meters or about 22 feet) and a no-charge semicircle under the basket. The official 3-on-3 ball has a 28.5-inch diameter — an inch smaller than the standard men’s ball, making it easier to grip and increasing the chances that shots go in.

— THE TEAMS: They’re made up of four players — three on the court, plus a substitute. The sub may enter at any dead ball from behind the end line — there’s no formal check-in process from the scorer’s table — once the player leaving the game makes physical contact (think slapping a high five) with him. Plus, coaches, either on the playground or in the bleachers, are forbidden.

— SCORING AND FOULS: You don’t call your own fouls in Olympic 3-on-3 ball — there are officials for that. Instead of merely keeping the ball on a shooting foul, players go to the free-throw line. Free throws are worth one point, and so are shots from inside the arc. Buckets from beyond the arc are worth two points. And there’s a 12-second shot clock and a rule specifically outlawing stalling or “failing to play actively (i.e., not attempting to score).”

— NO MAKE IT, TAKE IT: Just like in pretty much all other officiated versions of the sport, if your team scores, the ball goes to the other team. They will either dribble or pass from directly under the basket — but not from behind the end line — to somewhere behind the arc and can begin play immediately without “checking” the ball. Defensive rebounds and steals also must be cleared to the arc, but of course, there’s no such restriction on offensive boards. After a dead ball, play starts after a check-ball — just like on the playground — and jump balls always go to the defense.

— STYLE OF PLAY: Forget about fast breaks — especially with what’s essentially a half court and the mandatory clearing of defensive rebounds and steals to the arc. Expect more screens, isolation plays, quick backdoor cuts and offensive players backing defenders into the post.

— END OF GAME: FIBA games are timed — one 10-minute period — but the first team with 21 points during regulation wins. If it’s tied after 10 minutes, an overtime period follows and the first team to score two points in OT wins.