LOS ANGELES — When Charlie Sheen’s antics forced a reduction in the number of episodes of “Two and a Half Men” this year, CBS executives turned to the best pinch-hit series in TV history: “Rule of Engagement.”

CBS is producing extra episodes of “Rule of Engagement” to fill the scheduling gap. The comedy — starring Patrick Warburton, Oliver Hudson, David Spade, Megyn Price and Bianca Kajlich — is about two couples and their often annoying friend. The series has been around since February 2007 as a midseason replacement to fill ratings voids. CBS just this year added it to its fall schedule.

This week, “Rule of Engagement” moves to 8:30 p.m. Thursdays because the William Shatner comedy “$*! My Father Says” has had trouble attracting viewers in that time slot.

The cast seems unfazed by the changes.

“We’re happy we can be here and work together,” Kajlich said. “It doesn’t feel like work. You come and have fun and play with each other.”

Kajlich’s been told by fans of the show how much they like that their characters laugh at each other. The secret? The four actors are friends and enjoy making each other laugh.

Toss in the irreverent comedy of Spade and “Rules” has the family silliness of “Home Improvement,” the fun relationship of “Mad About You” and the cheekiness of “Seinfeld.”

Though the show hasn’t had enough time-slot consistency to build a larger fan base, CBS executives are confident enough to schedule it when and where it’s needed.

The move to Thursday is a little like starting over for the series.

The cast is optimistic because Thursday has been a great night for comedy and the “The Big Bang Theory” has the time slot before them, which should get viewers tuned to CBS.

“If the ratings go up, it’s exciting,” said Kajlich. “It’s been frustrating for us mostly because we’re putting something out that we really want our fans to see. When you have people come up to you and say, ‘I’m so sorry that this show was canceled,’ that’s frustrating.

“The great thing about it is, we are the little engine that could. We keep chugging along.”

‘Rules of Engagement’

When: 8:30 p.m. Thursday

Where: CBS