Advanced format ruling
Savage Colosseum
Card effect (current official text)If a monster attacks, at the end of the Damage Step: Its controller gains 300 LP. All monsters must attack, if able. During each End Phase: Destroy all face-up Attack Position monsters the turn player controls, that did not declare an attack.
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.