The NFL has announced the rule changes for 2013 with three big modifications:

1 – The “tuck rule” is gone!

2 – The crazy “red flag rule” that hosed the Lions and Falcons last year has been changed.  It will still be a penalty for “unnecessary challenge” (or however they word it), but officials will still review the play.

3 – Likely the most difficult new rule is that a “runner in the open field cannot  lower his head and initiate contact with a defender with the crown (top) of his helmet“.  This has been legal since day one, and now suddenly isn’t, which could take some adjustments by ball carriers.

Mark over at Football Zebras has a great review of the changes that is certainly worth reading.