Law 11 / An interactive explainer

Offside,
Explained

Drag players around a live pitch, replay the classic controversies, and never lose the offside argument again. World Cup ’26 edition — built for the group chat.

Start with the basics Make the call yourself

The essentials

Five minutes to never being wrong again

01 / The rule in one breath

What offside actually is

You're offside if you're involved in play while closer to the goal than both the ball and the second-last defender at the moment a teammate plays the ball. That's the whole law. When it's broken, the assistant referee patrolling the sideline raises a flag, play stops, and the defending team gets the ball. Everything else — every replay, every pub argument, every VAR line (that's the Video Assistant Referee, soccer's TV-replay check) — is detail hanging off that one sentence.

Notice what it doesn't say: nothing about where you are when you receive the ball, and nothing that outlaws simply standing in an offside spot. [Law 11]

FIG. 01 — A is beyond the second-last defender when P plays the ball — offside position. (Striped discs attack: A receives, P passes. Navy discs defend; GK is the goalkeeper.)

02 / The moment of the pass

The photo is taken at the kick

Offside is judged at the instant the ball leaves the passer's foot — not when it arrives. Think of it as a photograph taken at the kick. A striker can collect the ball twenty meters behind the entire defense and be perfectly onside, as long as he was level or behind the line in that photo.

This is the single most misunderstood thing in soccer, and the number one reason your buddy yells at the TV. He's looking at where the striker is; the linesman is remembering where he was.

FIG. 02 — Onside at the pass (ghost), a mile past the line at the touch — perfectly legal.

03 / The second-last defender

The line is a player, not a place

The offside line is drawn through the second-last opponent — and the goalkeeper counts as an opponent like anyone else. Ninety-nine times out of a hundred the keeper is the last man, so the line sits on the last outfield defender. But if the keeper charges upfield, the two last opponents might both be center-backs.

Level is onside.If any part of you that can legally score is exactly level with the second-last defender, you're fine — ties go to the attacker, and they have since 1990. [Law 11.1]

FIG. 03 — The keeper is the last man, so the second-last opponent is D1 — the line sits on D1, not the keeper.

04 / The ball and the halfway line

Two more lines protect you

You can never be offside behind the ball, and never in your own half. A striker who takes a cut-back pass — the ball rolled backward from the byline, the end line of the field beside the goal — is always onside, no matter how many defenders he's beaten, because the ball itself is deeper than he is.

And against a suicidally high defensive line, a forward can loiter a step inside his own half, beyond every center-back, and sprint clean through when the long ball comes. The effective offside line is always the most advanced of the three: second-last defender, ball, halfway line.

FIG. 04 — A is beyond every outfield defender but still in his own half — the halfway line saves him.

Your turn

Be the linesman

LIVE · IF PLAYED NOWOFFSIDEFlag up — play stops; the defense gets the ball (a free kick)

A: +3.0 M BEYOND THE LINE

Drag anyone — the call updates live. Then:

If the ball were played now:

A is beyond the second-last defender at the moment of the pass — offside position.

A plays the ball — interfering with play. Offence.

05 / Position isn't a crime

Standing there is legal

Being in an offside position only becomes an offence when you get involved. Involved means one of three things: you play the ball, you interfere with an opponent (block the keeper's view, challenge for the ball), or you gain an advantage from your position — like tapping in a rebound.

A striker parked offside while play flows to the other wing has committed no offence at all. That's why the flag sometimes stays down when someone looks flagrantly offside — the officials are waiting to see if he actually touches it.

FIG. 05 — The pass goes to B. A, though offside, touches nothing and nobody — play on.

06 / The three free passes

No offside from these restarts

There is no offside directly from a goal kick, a throw-in, or a corner kick. Camp as deep as you like. The exemption only covers the first touch, though — the moment a teammate plays it after the restart, normal offside rules snap back on.

Why these three? Tradition, mostly — but it's also why you'll see forwards standing shamelessly behind the entire defense at long throw-ins, and why nobody raises a flag about it.

FIG. 06 — A long throw-in finds A beyond the line — and it's completely legal.

Advanced mode(the official law text, deeper “why” notes, and a new “how the ball arrives” control on the pitch above)

Position vs. offence

Law 11.1, abridged —“A player is in an offside position if any part of the head, body or feet is in the opponents' half (excluding the halfway line) and nearer to the opponents' goal line than both the ball and the second-last opponent. The hands and arms of all players, including the goalkeepers, are not considered.”

The law is a two-step test. Step one is pure geometry (position); step two is behavior (offence). The interactive pitch above computes step one live and lets you flip the step-two inputs in this mode.

What counts as “level”

Only body parts you can legally score with count — head, body, feet. Arms and hands never count, for attackers or defenders. That's why semi-automated offside renders skeletons: the question is whether your shoulder (legal) or your armpit lineis past the defender's knee. A striker's outstretched arm being beyond the line is irrelevant.

Interfering with play

Playing or touching a ball passed or touched by a teammate. The simplest offence: if you were offside in the photo and the ball reaches you from your team, the flag goes up the moment you touch it.

Interfering with an opponent

You never need to touch the ball. Blocking the keeper's line of sight, challenging an opponent for the ball, or making an obvious action that affects a defender's ability to play it — all offences from an offside position. This is the one that catches strikers standing “passively” in front of the keeper on shots: passive in body, guilty in law.

Gaining an advantage

Playing a ball that rebounds to you off the post, the crossbar, an official, or an opponent — including a keeper's save — when you were offside at the original shot or pass. This is the “rebound trap”: offside at the shot means the tap-in doesn't count.

Deliberate play vs. deflection — the hard one

If a defender deliberately plays the ball — even by a deliberate handball, which is still a foul in its own right — the offside slate is wiped clean; an attacker in an offside position can legally take it. But a deflection, block, or savedoesn't reset anything. IFAB's criteria for “deliberate play”: the defender had time to coordinate his movement, the ball wasn't moving too fast or from too close, he could see it, and it wasn't an instinctive stretch or reaction. A baddeliberate clearance still resets offside — being terrible at it doesn't make it a deflection.

VAR, delayed flags, and the robots

Since VAR, assistants are told to keep the flag down on tight calls in attacking moves and let play run — that's why you see “late” flags after the ball hits the net. The goal is reviewable evidence: if the flag kills the move early, a wrong call can't be fixed. Semi-automated offside (used at World Cups since 2022) tracks limb positions many times per second and auto-alerts the VAR room; the ’26 tournament uses it too. The decision is still announced by a human — but the line is drawn by machines, which is why “level” arguments have gotten very, very quiet.

What this unlocks on the pitch

With advanced mode on, the “Be the linesman” pitch lets you change how the ball arrives — teammate pass, goal kick, throw-in, corner, deliberate defensive play, or deflection — and watch the same geometry produce opposite rulings. The verdict panels everywhere also show the deeper “why” behind each reason.

The classics

Nine calls that end friendships

A times his run to stay level with the last line…

00:00.0 / 00:03.6

Dead level with the second-last defender? That's onside — ties go to the attacker.

Prove it

Offside or not?

Q 1/12easy

Through-ball toward A, who's parked well beyond the back line when it's played.