3x3 basketball returns at Paris 2024 for its second Olympic appearance. Popularized at the grassroots level, this high-paced version of basketball differs from its traditional 5-on-5 counterpart in many key ways. Read on to learn more about the rules of 3x3.

Each roster consists of four players. As the name suggests, 3x3 basketball is played with three players on the court for each team. However, both teams are allowed one substitute throughout the game. This substitute can be "tagged in" during a stoppage of play, allowing for other players to rest on the bench.

Whereas traditional basketball games use a full court with hoops at both ends, a 3x3 court consists of a half court with one basket. Under FIBA (International Basketball Federation) regulations, official 3x3 courts measure 15 meters (about 49 feet) wide along the baseline and 11 meters (about 36 feet) long along the sidelines.

Yes, 3x3 uses a slightly smaller ball that allows for better ball handling and complements the increased speed of the game.

In 3x3, a field goal from beyond the arc is worth two points, and a field goal taken from inside the arc is worth one point. (In traditional basketball, these are worth three and two points, respectively.) Free throws are worth one point each — the same as in a traditional basketball game.

The first team to score 21 points gets the victory in 3x3. If neither team is able to score 21 points within 10 minutes, the team with the most points during that time period wins. If overtime is necessary, the first team to score two points earns the victory.

At the beginning of each game, a coin toss helps determine which team gets the ball first. The team that wins the coin toss has the option of starting the regulation period with the ball or opting to wait until a potential overtime period to receive the first possession.

After a dead ball situation, players from both teams execute a "check ball" (a swift exchanging of the ball between the offensive and defensive player) behind the two-point arc. Check ball situations are not executed after a team scores a field goal.

After any play that results in a change of possession (successful field goal, defensive rebound, steal, block), the ball must be cleared by dribbling or passing to a teammate behind the two-point arc. Following a successful field goal, a defensive player will play the ball from a semi-circle located directly below the hoop. While a competitor is playing the ball within the semi-circle, players from the opposing team are not allowed to attempt to steal the ball or physically impede their ability to make a play.

In a jump-ball situation, possession goes to the team that was previously on defense.

Fouls work similarly to how they do in traditional basketball games. If a player is fouled in the act of shooting, that player is granted one or two free throws (depending on whether or not the shooter was behind the two-point arc) if they miss the shot. If the player makes the shot, then the field goal counts and the player receives one free throw attempt. 

Fouls are charged to the team rather than the player. Each team is allowed a total of six fouls before entering the foul penalty situation. At that point, the opposing team will receive two free throws regardless of what type of foul was committed. Starting with the 10th team foul, the opposing team will also get possession of the ball in addition to the two free throws.

There is no fouling out for individual players in 3x3 basketball, but a player can get disqualified by committing two unsportsmanlike fouls during the course of a game.

The shot clock in 3x3 is 12 seconds (half of the 24-second shot clock used in traditional basketball). If the offensive team fails to take a shot before the shot clock expires, it results in a turnover.

Each team receives one, 30-second timeout per game. These are in addition to two TV timeouts per game which are called by the officials.