Advanced format ruling
Alien Kid
Card effect (current official text)Place 1 A-Counter on all monsters Special Summoned to your opponent's side of the field. (If a monster with an A-Counter battles an "Alien" monster, it loses 300 ATK and DEF for each A-Counter during damage calculation only.)
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.