Laws of the Game
High school, college and IFAB: what actually changes
A US referee can work a club match on Saturday and a high school match on Tuesday. These are the differences that change what you do, not just what you know.
High school soccer in the United States is played under NFHS rules, college soccer under NCAA rules, and almost everything else under the IFAB Laws of the Game as adopted by US Soccer. The offences are broadly the same — a foul is a foul, offside is judged the same way — but the match management around them is not.
The differences at a glance
| What | IFAB / US Soccer | NFHS (high school) | NCAA (college) |
|---|---|---|---|
| Who keeps time | The referee, on the field | A timer at the table, with a visible clock | A timer at the table, with a visible clock |
| Clock direction | Counts up, with time added at the end of each half | Counts down, and stops on the referee's signal | Counts down, stopped clock |
| Periods | Two halves of 45 minutes | Two halves of 40 minutes, or four quarters of 20 | Two halves of 45 minutes |
| Substitutions | Limited by competition, commonly five; no re-entry | Unlimited, with unlimited re-entry | Unlimited, at any stoppage, with limited re-entry |
| A cautioned player | Stays on the field | Must leave the field and may be substituted | Stays on the field; the clock stops |
| Officiating system | Diagonal system: referee and two assistants | Diagonal, dual or three-whistle systems are all used | Diagonal system, with a fourth official at higher levels |
| Video review | VAR where a competition uses it | None | Coaches' challenges where adopted |
Sources: the NFHS Comparative Study and rules summary, the NCAA soccer rules book and the Laws of the Game. Each governing body publishes its own changes on its own schedule, so confirm the current season's edition before you referee.
The clock is the difference you feel first
Under the Laws you are the timekeeper: the clock runs, you decide how much time to add, and your whistle ends the half. In a high school match the clock is on the scoreboard, counts down, and stops when you signal — for a goal, a card, an injury or a penalty kick. You are no longer the clock; you are telling the clock what to do, and a pre-match word with the timer about your signals saves an argument later.
That also changes what "added time" means. There is no added time to announce when the clock stops for stoppages: the stoppages come out of the clock as they happen.
Substitutions change the rhythm of the match
Unlimited substitutions with re-entry means players come and go all match. Expect more restarts to be substitution moments, and expect the technical area to be busier than in a club match. Under the Laws, by contrast, a substituted player is finished for the match in most competitions, so the same sequence needs a different management touch.
Cautions have a bigger consequence in high school
A caution under the Laws is a note in your book and nothing else changes. In a high school match a cautioned player leaves the field, which means the card also costs their team a body on the field until a substitution is made. Players and coaches feel that, so be ready for the reaction and keep the sequence tidy: show the card, record it, manage the substitution, restart.
Youth competitions modify the Laws too
Below high school, youth competitions in the US commonly modify the Laws in ways the Laws themselves allow: shorter periods, small-sided formats, a build-out line in the younger age groups, restrictions on heading, and unlimited substitutions. These vary by state association and league rather than nationally, so the rules of competition you were sent are the authority for your match — read them before kick-off.
What doesn't change
Offside, fouls, handball and misconduct are judged the same way in all three codes, and a card is still a card. What changes is the machinery around the decision: who keeps time, who can come back on, and what happens to a cautioned player.
Check your competition's own rulesThis page explains the differences in our own words and links to each governing body's published rules; it is not a substitute for them, and it does not cover every case. Written against Laws of the Game 2026/27 and the current published NFHS and NCAA materials. Halfline is not affiliated with or endorsed by The IFAB, FIFA, US Soccer, the NFHS or the NCAA. Last reviewed .