here’s a lot more to competitive Ultimate Frisbee than just throwing a disc.

The USA Ultimate… There’s a lot more to competitive Ultimate Frisbee than just throwing a disc.

The USA Ultimate website describes Ultimate as “combining the nonstop movement and athletic endurance of soccer with the aerial passing skills of football.”

Ultimate is played on a 70-by-40-yard field with end zones 25 yards deep. The disc is thrown from player to player — with seven players on a side — and the players cannot run with the disc.

Athletes can only move one foot, in a movement known as pivoting, while holding the disc.

Ultimate players line up seven on seven and the cutting takes place in a similar manner to soccer. The object is to score points by passing to a player in the opposite team’s end zone like in football. Substitution is only allowed after a point is scored.

Each point starts with the teams lined up in front of their end-zone lines. The defense then throws the disc to the offense.

The disc changes possession the instant it touches the ground, goes out of bounds, is intercepted or when a player holds the disc for more than 10 seconds.

Ultimate is played with 175-gram Discraft discs ­— the official discs of the sport.

No physical contact is allowed and the game is self-officiated. That is, players call their own fouls.

Fouls and contact rules are very similar to those in basketball and usually fouls occur when two players are going for a disc and one grabs an arm or makes too much contact with the body. This can be compared to a foul that would occur when a player drives to the hoop in basketball.

Unlike in basketball, however, picks and screens are illegal.

Any dispute over a foul is referred to one of four on-field “observers,” who act as judges and only intervene on a disputed call. At USAU Nationals, these observers make active calls for completions and incompletions, as well as out of bounds.

Games at Nationals will be played to 15 points.

“It used to be that people didn’t start playing Ultimate until their freshman year of college, but what we have been seeing lately is more and more leagues in Pittsburgh and Philadelphia, which is great,” Pitt Ultimate assistant coach David Vatz said. “We are now getting tons of kids who not only played in high school but also played competitively, and it’s given us a tremendous advantage.”

There have been a few attempts to start professional Ultimate leagues, such as Major League Ultimate, but none have succeeded. The USA Ultimate website says that the sport is played in more than 42 countries by thousands of athletes.