Futsal and Indoor Soccer — How the Rules Differ
Futsal is a FIFA game with its own Laws; American arena soccer played off the boards is something else entirely. Here is what changes, and why futsal is worth your winter.
Say "indoor soccer" in the United States and you could mean two completely different games. One of them is futsal, a FIFA sport with its own Laws of the Game, played on a hard court with no walls. The other is arena or indoor soccer, played off the boards in a hockey rink, with rules written by whoever owns the building.
They look similar from the parking lot. They are not the same game, and if you are signing up for a winter league it is worth knowing which one you are joining.
Futsal
Futsal is the small-sided game most of the world's great players grew up on. The name comes from fútbol sala — hall football — and it is deliberately, aggressively about the ball at your feet.
The court and the goals
A futsal court is 40 × 20 metres for FIFA competition, which is roughly the size of a basketball court, and many American clubs play on exactly that. There are no walls: the ball goes out, and play restarts.
The goals are 3 metres wide by 2 metres high — much smaller than a soccer goal, which is why goalkeeping in futsal is about shot-stopping angles rather than crosses.
There are two penalty marks: the first at 6 metres, and a second at 10 metres that exists for one specific purpose, described below.
The ball is the whole point
A futsal ball is size 4 but not a size 4 soccer ball. It is heavier — roughly 400–440 grams against a size 5's 410–450 — and, crucially, it has a reduced bounce. Drop it and it barely comes back.
That single property is what makes futsal work. The ball stays on the floor, so you have to pass it and control it rather than launch it. Play a winter of futsal and your first touch on grass in the spring is noticeably better. That is not folklore; it is what the equipment forces you to do.
The clock, and how different it feels
Two halves of 20 minutes, and the clock stops whenever the ball is out of play — so a 40-minute match is 40 actual minutes of soccer, and it is exhausting. FIFA's own summary puts it plainly: "The 20 minutes represent the actual playing time, as the clock is stopped whenever the ball is not in play."
Each team gets one time-out of one minute per half, which can only be called when that team has the ball.
Five a side, and endless substitutions
One goalkeeper and four outfield players. Up to nine more players on the bench, substituted on and off an unlimited number of times, on the fly, hockey-style, through a designated zone. Shifts are short because the game is brutal.
The four-second rule
The rule that keeps futsal fast. If the goalkeeper has the ball, "he must play it to a team-mate within four seconds, regardless of whether the ball is in his hands or at his feet."
The same four seconds apply to restarts — kick-ins, corner kicks and free kicks all have to be taken within four seconds, or possession changes.
Kick-ins, not throw-ins
When the ball crosses the touchline it comes back with the foot, from the line, within four seconds. No throws at all. Corners and free kicks are otherwise familiar.
Accumulated fouls and the 10-metre kick
This is futsal's cleverest invention. Every direct-free-kick foul a team commits in a half is counted. On the sixth accumulated foul and every one after it, the other team gets a free kick from the second penalty mark, 10 metres out, with no wall — just the kicker and the goalkeeper.
It is very close to a penalty. The effect is that teams cannot foul their way out of trouble, because the fifth foul of a half changes how everyone defends.
Goalkeeper restrictions
Beyond the four seconds, a futsal goalkeeper who has released the ball generally may not receive it back in their own half until an opponent has touched it or they have entered the opposition half. It stops a team simply passing back and forth with the keeper to kill time.
No offside
None. "There is no offside in futsal." One less thing to argue about, and one reason it is such a good format for young players and new referees.
American indoor and arena soccer
The other winter game is played in a rink with walls, and the walls change everything: the ball stays live off the boards, there are no kick-ins, and play is continuous in a way futsal is not.
Beyond that, be careful about generalising. Arena and indoor soccer in the United States is run by individual facilities and leagues rather than by FIFA, so field size, roster size, period length, substitution rules, whether there are penalty boxes for fouls, whether there are lines you cannot pass the ball over in the air, and whether the walls count for a legal goal all vary from building to building.
Ask the facility for their rules sheet before your first game. Every league has one, and they are usually a single page. That is a far better guide than anything a national article could tell you.
Which should you play?
Play futsal if you want to get better. Small court, heavy low-bouncing ball, no walls to bail you out, constant decisions. It is the best technical training disguised as a game that exists, and it is why so many national federations now push it for young players.
Play arena soccer if you want a fast, high-scoring, sociable game and you like the walls. It is enormous fun, and the continuous play means less standing around than futsal's stopped clock.
Play both if your winter allows it. They train different things.
Practical notes
Shoes. Flat gum-soled indoor court shoes (marked IN or IC) for futsal on a wooden or sport court. Turf shoes (TF) if your "indoor" facility is actually short-pile turf. Never studs on a court — you will slip, and the building will ask you to leave. Our cleat guide covers the letters on the box.
Shin guards. Required in futsal, as in soccer, and sensible in arena soccer whatever the league says.
The ball. If you are buying one, get an actual low-bounce futsal ball. A size 4 soccer ball on a hard court is a different and much worse experience.
Goalkeepers. Futsal keepers need reactions and distribution far more than they need to catch crosses, and padded pants matter more than gloves on a hard floor.
Looking for somewhere to play this winter? Find futsal and indoor soccer near you, state by state. New to the outdoor Laws too? Start with the 17 Laws in plain English.
Sources. Futsal specifics are from FIFA's Futsal Laws of the Game and FIFA's own published summary of them. American arena and indoor soccer has no single governing rule book, which is why this guide describes it only in general terms.