Goat format ruling
Attack and Receive

Card effect (current official text)You can only activate this card when you take damage to your Life Points. Inflict 700 points of damage to your opponent's Life Points. Also, inflict 300 points of damage to your opponent's Life Points for each "Attack and Receive" card in your Graveyard.
Rulings
"Attack and Receive" may not be activated in response to payment of a Cost.
- "Attack and Receive" may not be activated in response to an effect that has the player losing LP, as opposed to taking Damage.
- "Attack and Receive" may not be activated in response to your own card effect, even if it inflicts damage to you.
- "Attack and Receive" may be activated in the Damage Step.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Goat forum — sourced change requests get reviewed.