One of the 2021 rule changes had to do with the Forward Pass in Rule 8, Section 1, Article 2.
ARTICLE 2. LEGAL FORWARD PASS.
The offensive team may make one forward pass from behind the line during each down.
If the ball, whether in player possession or loose, crosses the line of scrimmage, a forward pass is not permissible, regardless of
whether the ball returns behind the line of scrimmage before the pass is thrown.
Item 1. Illegal Passes.
Any other forward pass by either team is illegal and is a foul by the passing team, including:
(a) A forward pass thrown when the passer is beyond the line of scrimmage.
Note: It is a forward pass from beyond the line of scrimmage if the passer’s entire body and the ball are beyond the line of
scrimmage when the ball is released, whether the passer is airborne or touching the ground. The penalty for a forward pass
thrown from beyond the line is enforced from the spot where the ball is released.
(b) A second forward pass thrown from behind the line of scrimmage.
(c) A forward pass thrown after the ball has crossed the line of scrimmage and has returned behind it.
(d) A forward pass thrown after there has been a change of possession.
Item 2. Intercepted Illegal Pass.If an illegal pass is caught or intercepted, the ball may be advanced and the penalty declined.
Penalties:(a) For a forward pass from beyond the line: Loss of down and five yards from the spot of the pass. See S.N. below.
(b) For a second forward pass from behind the line, or for a forward pass that was thrown after the ball returned behind
the line: Loss of down and five yards from the previous spot.
(c) For a forward pass that is thrown after a change of possession: Loss of five yards from the spot of the pass.
Notes:(1) Eligibility, pass interference, and intentional grounding rules apply when a forward pass is thrown from behind the line,
regardless of whether the pass is an illegal forward pass. Eligibility, pass interference, and intentional grounding rules do
not apply if a forward pass is thrown (a) from beyond the line, (b) on a Free Kick play, (c) on a Fair Catch kick play, or (d)
after a change of possession.
(2) Roughing the passer rules apply on all passes (legal or illegal) thrown from behind the line of scrimmage (12-2-9). If a
pass is thrown from beyond the line of scrimmage, unnecessary roughness may apply for action against the passer.
(3) When a distance penalty in Penalty (a) leaves the ball in advance of the necessary line to gain, it is first-and-10 for the
offensive team.
(4) See 3-2-4 for the definition of team possession during a forward pass (a loose ball), or for when possession ends