Edison format ruling
Code A Ancient Ruins

Card text as printed in this era① If a face-up "Alien" monster(s) is destroyed, place 1 A-Counter on this card.
② Once per turn:
You can remove 2 A-Counters from the field;
Special Summon 1 "Alien" monster from your GY.
Rulings
- If a Set "Alien" monster is destroyed by battle, you do not place A-Counters on this card. (It needs to be face-up at attack declaration).
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Edison forum — sourced change requests get reviewed.