Silver Age includes all the figures from Superior Foes of Spider-Man and newer. Figures in this format all have the dial printed on the back of the card. This includes all exclusive and promotional figures. Typically this will include all figures whose collector number year shows 17 and up (such as M17, MP17, F17, etc.). As long as the character card follows the indicted card format as introduced in Superior Foes of Spider-Man, the game element is legal for a Silver Age event (unless it is a banned game element).
Please see the figures/game elements banned for Silver Age below, as well as the Silver Age Watch List. In the future, figures/game elements might be banned in Silver Age even if they’re legal in Modern Age, since the needs of the formats are different.