What Is Clipping? The NFL Low Block From Behind Rule

Clipping is blocking an opponent who is not the runner from behind and below the waist. In the NFL it normally carries a 15 yard penalty. The rule includes narrow exceptions and contact distinctions, so neither every low collision nor every block from behind is clipping.

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The first questions are who has the ball, where the block begins and where contact lands.

Angle and height distinguish the foul

A conventional block in the back involves contact from behind above the waist. Clipping concerns the lower contact. A block from the side may instead raise another rule, depending on the blocker, location and direction.

Tackling the runner is a different act. The clipping restriction protects a nonrunner, such as a defender pursuing the ball while an offensive teammate blocks him.

That does not make any tackle automatically legal. The league has separate restrictions for prohibited contact against runners.

The close line exception is limited

The NFL permits certain offensive clipping above the knees during defined close line play. It does not permit clipping at or below the knees.

The exception also excludes the specified case of an offensive lineman clipping a defender who was aligned opposite another lineman more than one position away and is moving with the ball's flow away from the blocker. An offensive tackle cannot use the exception to clip a nose tackle on a sweep away.

Close line play is its own defined term. It is not a blanket exception for anything near the tackle box or inside run action.

What the full sequence can change

If an opponent turns his back during a block, the action is not clipping when he could see or ward off the block. Continuous contact that begins legally from the side while both players move in the same direction can also be treated differently from a new block delivered from behind.

But a blocker rolling onto the back or side of a defender's legs after a block is clipping, including during close line play. A legal start does not excuse that finish.

Compare the neighboring rules

A chop block involves a prohibited combination of blocks against the same defender. A blindside block focuses on the blocker's path and forcible contact with specified body parts. A peel back block has a directional and low contact test of its own.

The correct ruling comes from the actual elements, not how surprising or violent the hit looked. The 15 yard distance also does not settle the next spot by itself; enforcement depends on the play and foul location.

Keep learning

• Blindside blocks: Compare direction and contact tools with clipping angle and height.

• Illegal crackback blocks: See the restrictions on blockers coming toward the snap location.

• Penalty enforcement: Learn why the foul spot changes the final result.

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Rules reviewed October 10, 2026. Official 2026 NFL rulebook. Rule 12, Section 2, Article 1 and Rule 3, Section 6.