For years now the major powers of the criminal underworld have been playing games with each other, games of chess. The pieces have been members of the players' organization or unwitting pawns, the board is the entire planet, and the games are overseen by a mysterious figure called the Grandmaster. But in all the games there was always one constant rule: Empire City was off limits. No superhuman activity, covert or otherwise, was allowed in the city's borders. The municipal government was secretly controlled by the Grandmaster and metahuman activity was officially discouraged. Then one of the players broke the rules.

The organization called the Crime Cartel was pitted against a super-secret government agency when they upped the ante. The Cartel kidnapped a group of professional wrestlers who were performing in Empire, gave them metahuman powers and brainwashed them into becoming agents for the organization. Several costumed adventurers were at the wrestling event and intervened. After defeating the members of the Cartel and the brainwashed wrestlers, these heroes decided to band together as the Guardians and took the Cartel's Empire City base as their new HQ. The original team consisted of:

Crossfire eventually left the team, as did Desperado. Both had professional commitments in their civilian lives that prevented them from staying. When the hero Galahad, now calling himself Paladin, returned to the present he immediately went into hiding. During his travels through time, he had learned the truth about the mysterious being called Omega and he needed allies, but could not trust any of his former teammates. He enlisted the Guardians' help, and along with the mysterious hero Zodiak they were able to defeat Omega and his plans of global domination. Afterwards, Paladin chose to stay with the team, and they were later joined by the heroine Frostbite at the onset of the Revelations crisis.

The team's roster underwent major changes during and following Revelations. Human Bomb lost control of his powers and left the team; Frostbite left for personal reasons; Desperado returned, only to disappear after helping locate the Grail during Revelations; and during a battle with Father Lucifer and Lucifer's 6, Omen was reduced to infancy. Many of the existing members were gone but they were soon replaced. Flashback had joined during Revelations; a bizarre set of circumstances saw Tazer's roommate become an officer of L.E.G.I.O.N. and join the team; and a new hero calling himself Maximize joined, as did the Titan Damage, who assumed the code-name Shockwave to hide his identity from federal authorities.

The team effectively ceased to exist after the coming of the Millennium Giants. Rift and Tazer had vanished, and Shockwave/Damage was lost at sea during the battle. Flashback left to find Tazer and Guardienne went looking for Damage. After this the two remaining members decided to go their separate ways; Maximize returned to college and Paladin took a vacation accompanied by his adopted son, the infant who had been the hero Omen.

Several months later, a new Guardians team emerged. Flashback had found Tazer in the mystic realm of Skartaris and they had returned to Empire. After learning that Damage had survived and was now a member of the Titans, a broken-hearted Guardienne also went home to Empire. Then the mysterious Harbinger arrived. He claimed to be an adult Damien Omen from the far future returned to combat some evil force. He recruited Flashback, Tazer, and Guardienne into a new Guardians. They were soon joined by the Human Bomb, once again in control of his powers, and by Torch.