Guardians of Order moved into the d20 market beginning with their new superhero role-playing game, Silver Age Sentinels (2002), which was written by Mark C. MacKinnon, Jeff Mackintosh, and Jesse Scoble, with Steve Kenson and was developed by Lucien Soulban.

[1]: 358  After Guardians of Order went out of business in 2006, White Wolf bought the IPs for some of the company's games, including Silver Age Sentinels.

[1]: 228 Dyskami Publishing Company, founded by Mark C. MacKinnon in 2013, has come out with Absolute Power, billed as the second edition of Silver Age Sentinels.

[2] Silver Age Sentinels features an original game world inspired by classic "four-color" DC and Marvel comic book series, updated to modern political and moral sensibilities.

Path of the Just (2003) featured an introduction by Denny O'Neil and included stories by John Ostrander, Steven Grant, and Ed Greenwood.