The NFL has posted the video shown to the players at training camps explaining the rules changes and points of emphasis for 2015. You can download the 8½-minute video here.
A quick summary of the rule changes:
- Point-after touchdown conversions will snap from the 15 for a kick and the 2 for a run or pass
- The defense may recover and score on a point-after-touchdown attempt.
- Clock errors at the expiration of the half greater than 1 second are reviewable with limitations
- Pushing into the line on a punt is illegal just as on a field goal or extra-point kick
- A receiver is in a defenseless posture from hits to the head/neck immediately following an interception
- Chop block exceptions for H-backs and tight ends removed
- Linebackers can be numbered 40-49
- Players reporting ineligible must be in tight formation where a lineman ordinarily would be
- Independent certified athletic trainers (ATC) may call for an injury timeout if a player exhibits concussion symptoms
- Retractable roofs may be opened at halftime if certain weather conditions are met (2015 season only)