Wikia

Original	First Errata
If your opponent's monster attacks a monster on your side of the field, you can activate this card during the Damage Step. Increase the ATK of your attacked monster by the ATK of 1 other face-up monster on your side of the field during the Damage Step.	If your opponent's monsters attacks a monster on your side of the field, you can activate this card during the Damage Step. Your attacked monster gains ATK equal to the ATK of 1 other face-up monster on your side of the field during the Damage Step only.
Rise of Destiny RDS-EN060 Added by Look234	Dark Revelation Volume 3 DR3-EN120 Added by Deltaneos

Card Errata:Covering Fire