An illegal screen occurs when a screener creates prohibited contact—for example, by stepping into an opponent without allowing room to avoid a collision, sliding into the opponent’s route, or extending an arm or leg to block passage. Movement alone does not settle the call: NBA rules allow a narrow exception when the players are already traveling in the same direction and path. NBA screening rule

The league’s September 29 release identifies screening freedom of movement among its 2026-27 points of emphasis, alongside offensive off-arm push-offs. The underlying screening restrictions already appear in the rulebook; the announcement itself does not establish how frequently officials will call them this season. NBA’s 2026-27 announcement

How much room must a screener leave?

The answer depends on whether the opponent is moving and can see the screen.

Against a stationary opponent who can see the screener in front or alongside, the screener can establish a position very close without initiating contact. Behind a stationary opponent, the screener must leave enough space for a normal backward step. Against a moving opponent, the screener must allow an opportunity to avoid contact. NBA’s official screening interpretation

Speed matters. Rule 12 explains that the required distance for a moving opponent can be one or two normal steps or strides. Stopping immediately before a collision does not, by itself, establish that the opponent received enough room. Rule 12, screening provisions

A handoff example in the NBA’s video library shows how this applies. After passing to a teammate, KJ Simpson continues forward into Scottie Barnes’ route. The league identifies an offensive foul because Barnes does not have an opportunity to avoid the contact. Completing the pass does not exempt Simpson’s next movement from the screening rules. NBA’s handoff example

When can a moving screen be legal?

The NBA permits two opponents to continue along the same direction and path, with the trailing player responsible for contact. The player ahead can slow down or stop, but cannot move backward or sideways into the opponent. Both players must already have been following that identical route before contact. NBA’s official interpretation

As a hypothetical illustration, a player running ahead of an opponent along the same lane can slow down without automatically committing a screening foul. That exception does not cover a screener who steps across a defender’s route to intercept him. Merely facing the same basket does not satisfy the same-path condition.

To judge whether the exception applies, watch the replay from before the collision so you can follow both players’ routes.

Watch the arms and legs, too

A screener’s lower body can appear set while his arms create the foul. In another official library example, Dalen Terry extends his arms into Ziaire Williams during a screen. The NBA identifies that extension and illegal contact as the offensive foul. NBA’s arm-extension example

Extending a leg to block passage can also be illegal. The league’s explanation of a Jakob Poeltl screen identifies his extended leg contacting Alex Caruso outside the vertical plane of Poeltl’s body. The accompanying guidance requires a screening stance no wider than shoulder width. NBA’s extended-leg example

The defender can commit the foul

Watch the defender’s actions during the screen as well. The NBA’s library includes a defensive foul in which Jaylen Brown wraps an arm around Rudy Gobert’s waist as Gobert sets a screen. The league explains that the hold restricts the screener’s movement; defenders cannot dislodge, reroute or impede an offensive player through illegal contact. NBA’s defensive-holding example

On a disputed replay, follow the approach, the space available and the action that causes the contact. A late step across the defender’s route, an extended arm and a defender’s waist-level grab can produce similar-looking collisions, but responsibility depends on who makes the illegal contact.