A quick glance across the primetime Emmy guest star nods quickly reveals most of the nominees look an awful lot like series regulars.

None of the women nominated stepped in for just a single episode, which has raised some hackles. While acceptable under Emmy rules, the question is being raised as to how fair it is to compare an actor coming in for just a limited guest shot vs. one who is a credit short of a recurring character.

Cloris Leachman may only pop out of the bedroom occasionally, but as the wacky grandma she’s still a part of the core family on “Raising Hope.” And Joan Cusack in “Shameless” often ended up in as many episodes as those deemed supporting actors.

Loretta Devine has appeared on “Grey’s Anatomy” since the show first launched, but checked in for a significant story arc on her character’s early stages of Alzheimer’s this season that earned her a nom.

Last year, John Lithgow took home the guest actor Emmy even though he appeared in almost every episode of “Dexter” as the Trinity Killer. Julia Stiles hopes to repeat that streak with her ongoing turn last season as Dexter’s partner in crime.

The rules regarding guest star criteria have constantly changed over the years. In the past, the TV Academy has limited the number of appearances an actor can make on the series in order to be considered a guest. According to the org’s senior VP John Leverence, at one time the appearances were capped at three. Then, recognizing story arcs, the number was upped to six.

Later, the rule was changed so the standards for being viewed as a guest actor hinged on the actor’s contract spelling out his credit on the show.

“The quantitative ground is always shifting on us, but the qualitative ground remains the same,” Leverence says. “How many episodes are appropriate seemed to change as drama changed. As we got more into ensemble casts, we entered into a new area of who are the leads, and who are the supports and, in turn, who are the guest stars.”

Margo Martindale, who guest starred on “Justified” for just one season, opted to submit in the supporting actress category this year. She snagged a nomination.

Leverence, however, maintains there is a difference between a guest actor and a series regular even if they recur on the show rather than just walk in for a single job.

“There’s an orbit around the mother planet of series and the regulars,” says Leverence. “The guest stars, no matter how many episodes they are in, are positioned differently than the core lead and support group.”

At this time, there are no plans to change conditions under which an actor may submit to this category.

“In a nutshell, board policy is to defer to the legal experts,” says Sheri Ebner, director of the Emmy Awards. “If the contract says they are a guest actor, then they are a guest actor.”

But as history proves, policy can always shift.

“The board might do a blend, where the title is one part and then a cap on the number of episodes another,” Leverence says. “There’s nothing on the agenda, but rules are constantly changing and evolving.”

Ebner says in the end, it doesn’t really matter how many episodes in which the actor appeared, but the power of the submitted performance.

It only took one appearance on “Law & Order: SVU” for Ann-Margret’s guest star Emmy win last season.

“It all comes down to that one episode, so that makes things equal, ” Ebner says.

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