Soccer has five rules that look weird if you grew up on American sports. The clock counts up. The referee, not a stadium timekeeper, decides when the match ends. Players get sent off without replacement. Substitutes are limited. Offside is a sentence-long rule no one can explain in one sentence. Each one comes from a specific decision the sport made about what it wanted to be.
Soccer has rules that look weird if you grew up on American sports. The clock counts up instead of down. The referee, not a stadium timekeeper, decides when the game ends. Players get sent off without replacement. Substitutes are limited. Offside is a sentence-long rule that no one can explain in one sentence.
Here are the five rules new fans ask about most. None of them are arbitrary. Each one comes from a specific decision the sport made about what it wanted to be.
1. The clock counts up because the referee is the timekeeper
In basketball, football, and hockey, the clock counts down to zero and the game ends when it hits zero. In soccer, the clock counts up to forty-five and ninety, and the game ends when the referee decides it ends.
The reason is that the referee is the official timekeeper. The clock on the broadcast and in the stadium is a display, not an authority. The referee carries the official time on their own watch and decides when each half is over based on that watch plus stoppage added for delays.
This is why a match can end at 90 minutes plus 4, plus 7, plus 12. The clock keeps counting up past 90, because the actual end of the game is not at 90. It is at 90 plus whatever the referee added.
2. Stoppage time is for delays, not drama
The added minutes at the end of each half are called stoppage time, or injury time, or sometimes added time. They exist because soccer does not stop the clock during play.
The clock keeps running for substitutions, for injuries, for goals being scored and celebrated, for VAR reviews, and for time wasted by players standing over a ball before a free kick. The referee tracks all of those delays during the half and adds the total at the end. A half with multiple long VAR reviews can run 8 to 12 minutes of stoppage. A clean half with no delays might run only 2.
Stoppage time used to be approximate. After the 2022 World Cup, FIFA pushed referees to count delays more strictly and add the actual measured stoppage rather than the customary 3 to 5 minutes. Modern World Cup halves now routinely show 8 to 10 minutes of stoppage at the end of the half.
3. Offside is about position, not movement
The simplest version of the rule. A player is offside if, at the moment the ball is passed forward by a teammate, they are nearer to the opposing goal than both the ball and the second-to-last defender.
The second-to-last defender almost always means the last outfield defender, because the goalkeeper is usually the last. So in practice: when a teammate plays the ball forward, you cannot be ahead of the last defender unless you started behind them.
Three things to remember.
- Position at the moment of the pass. The check happens at the instant the ball is played, not when the receiver gets it. A player can sprint past the defenders after the pass and be onside, as long as they started level or behind them. - Only forward passes count. A back-pass cannot put you offside. - Active involvement. Being in an offside position is not itself a foul. You have to be involved in the play, by playing the ball, interfering with an opponent, or gaining an advantage from your position.
The reason offside exists is to stop teams from parking a single attacker permanently next to the goalkeeper and pinging long balls forward. Without it, the entire shape of the game collapses.
4. Yellow and red cards are not strikes
A yellow card is a caution. The player stays on the field. A second yellow in the same match becomes a red. A straight red, given for a severe foul or violent conduct, ejects the player immediately.
The critical part. When a player is sent off with a red card, the team plays the rest of the match a player short. There is no substitution to replace them. Eleven becomes ten. Ten can become nine if a second player picks up a red.
Yellow cards also carry over. If a player accumulates two yellow cards across separate group-stage matches, they are suspended for the next match. Yellow cards reset before the quarterfinals so a player carrying one yellow into the knockout rounds cannot be suspended out of the semifinal by a single quarterfinal caution.
5. Substitutions are limited to five, used in three windows
A World Cup team can make five substitutions per match. The catch is that all five must come from the bench during one of three substitution windows, plus halftime. A team that uses one substitution window for a single sub has used one of its three available windows for the rest of the match.
The rule was raised from three substitutions to five during the 2020 pandemic and stayed there. The three-window restriction was added to prevent teams from breaking the flow of the game with constant single-player swaps.
Substitutions made at halftime do not count against the three windows. They do count against the five total subs.
If a match goes to extra time, the team gets an additional substitution, for a total of six, and an extra substitution window. Substitutions cannot be reversed. Once a player is replaced, they cannot return to the match.
Why this matters for the 2026 World Cup
All five of these rules play differently than they would in a domestic season, because the World Cup is short, the stakes per match are higher, and the field has just been expanded. Fair-play points, set by yellow and red cards, can decide who advances to the Round of 32 as a best third-place team. Stoppage time can add ten minutes to a tied knockout match. A red card in the second half of a knockout game can decide a tournament.
If you are new to the sport and watching for the first time, these five rules cover roughly ninety percent of what looks weird from the outside. The rest is just culture.
For the tournament format and how the eight best third-place teams qualify, see How Do the Best Third-Place Teams Advance. For the US host cities and how to watch, see What Time Is the Game.